Nowadays you won’t surprise anyone with a digital camera - probably every family has one. Both young and old take pictures; The quality of the photographs leaves much to be desired: many photographs seem to be shrouded in some kind of fog; the bright blue sky looks gray on them, the sunset is not at all as amazing as you thought when shooting; Objects that are quite visible during the photographing process appear in deep shadow in the resulting images, etc. Of course, you don’t want to show such photos to friends and acquaintances, or print them. If the pictures reflect truly important moments in your life, then you can try to improve them using one or another software tool. However, not all users have the necessary experience for this, and it takes a lot of time to correct photos.
A more than urgent task arises: how quickly and with minimal preparation (or no preparation at all) can be done to improve the moments captured on the camera. Of course, we are not talking about obtaining masterpieces of photographic art from the point of view of professional photographers, but simply about improving the brightness, contrast and saturation of images, and adjusting them color range, stretching shadows, etc. If the appropriate corrective operations are carried out correctly, you can get natural and attractive photographs from seemingly irretrievably lost low-quality images.
The question is what software solutions can provide such transformations in automatic mode and with the least effort for the user. There are possible options here... Theoretically, minimal capabilities for basic auto photo correction are now provided even in ordinary graphics viewers, such as XnView, IrfanView, etc. However, to change incorrect setting exposure, correcting poor color reproduction, sharpening the image, etc. It makes more sense to turn to more suitable products - specialized programs for improving images or comprehensive solutions for image processing (photo editors and photo organizers). We will look at some such programs in this article. But first, let’s clarify a number of rules that should be followed to carry out successful auto-correction.
Rules you shouldn't forget about
- Auto-correction of pictures that have already been subjected to some kind of artistic processing (for example, effects and frames have been added to the photo) will most likely be unsuccessful. Any “decoration” of images is carried out only at the final stage, after all the required correction operations: noise removal, color correction, sharpness adjustment, etc.
- Don't try to correct photos with different software one at a time, since during such transformations in some solutions some important information about the image is deleted - as a result, the results of auto-correction in other software products may turn out to be completely unpredictable.
- If you use filters with your camera that create various effects when taking photographs, then be prepared for the fact that the effect may be canceled during automatic correction. Therefore, it is possible that to improve such images, photographs will have to be adjusted manually.
Specialized programs for improving images
There is not much highly specialized software for improving (or, as they say, optimizing) images on the market; We will focus on the most popular programs among users: Photomizer, PhotoPerfect Express, Ashampoo Photo Optimizer and SuperEasy Photo Booster. They in no way pretend to replace full-fledged editors for image processing, but nevertheless they allow you to correct digital photographs, and without the slightest difficulty (literally a couple of mouse clicks). In addition, these solutions do not require the user to have any global knowledge of correction (there is also no need to study lengthy manuals), so understanding them is not a problem.
To optimize images in any of these programs, it is enough to indicate the image being processed (it is possible to improve tens or hundreds of photos at once in batch mode) and start the transformation process by clicking on the appropriate button, and then save the final image. And that's it - your pictures will become more expressive and more realistic almost in the blink of an eye (Fig. 1).
Rice. 1. Examples of image optimization in Photomizer
Photomizer 2.0
Developer: Engelmann Media GmbH
Distribution size: Photomizer - 18 MB; Photomizer PRO - 30.4 MB
Work under control: Windows XP/Vista/7/8
Distribution method: shareware (3-day demo - ftp://ftp.engelmann.com/photomizer.exe ; ftp://ftp.engelmann.com/photomizer-pro.exe)
Price: Photomizer - 29.99 euros; Photomizer PRO - 49.99 euros
Photomizer is a simple solution for quickly improving photos, including in batch mode. The program can automatically correct color and exposure errors, improve insufficiently clear images and improve the level of illumination in areas of light and shadow. It can also be used to eliminate noise and remove artifacts resulting from JPEG image compression. In practice, this solution shows impressive results when processing images with irregular or muted colors (the latter often occurs when shooting underwater), blurry or foggy landscapes, photos taken in adverse weather conditions or in low light, old scanned photos, etc. To save time, the program comes with preset input profiles that are configured to optimize digital camera photos, slides, negatives, webcam photos, scans, and stills captured mobile phone(it is possible to create custom profiles). The program is presented in two editions: basic Photomizer and extended Photomizer PRO; the latter is equipped with a more solid set of built-in input profiles and additionally includes tools for eliminating distortion, as well as applying simple effects and frames.
Any transformation in Photomizer can be performed, in fact, in several steps - just load the image, select the input profile and check the boxes of the operations of interest (Fig. 2), although if you wish, you can intervene in the transformation process by changing the degree of impact of a particular operation on image. Processed photos are saved in JPG formats or BMP. It is possible to optimize hundreds of images at once in batch mode.
Rice. 2. Quick auto photo correction in Photomizer
PhotoPerfect Express 1.0
Developer: Arcadia Software
Distribution size: 40.9 MB
Work under control: Windows XP/Vista/7
Distribution method: freeware (http://www.photoperfect.com/download.html)
Price: free, but to use a number of features (some algorithms and batch processing) purchase required license keys: i?e Standard algorithm - $24.99; i?e Professional algorithm - $94.99; Perfectly Clear algorithm - $49.99, Batch and More module - $15, etc.
PhotoPerfect Express is simple and convenient program to quickly improve your photos. It implements five image optimization algorithms: RGBMax, YMax, Xe847, i2e and Perfectly Clear - the first three can be used for free; the other two are offered on a commercial basis (when using commercial algorithms without payment, a watermark is installed on the images). Each of the algorithms in its own way improves the image by adjusting color, brightness, contrast, sharpness and a number of other parameters, and the result, as a rule, is noticeable better than the original(this statement also applies to freely available algorithms, so many users do not need to purchase keys to commercial tools). Although everything, of course, depends on the original image, for example, to improve faded and faded photos, as well as images with deep shadows, it is better to use the Perfectly Clear algorithm, when processing landscapes or images taken in daylight, the Xe847 algorithm demonstrates excellent results, using which manages to bring a digital photograph to the form the photographer saw it at the time of shooting, etc. When using the i2e and Perfectly Clear algorithms, auto-correcting a photo can also eliminate red-eye and minimize noise. It is worth noting that when using the last three algorithms, it is possible to fine-tune a number of optimization parameters manually, taking into account the individual characteristics of the processed photo, which allows you to achieve even more impressive results.
Carrying out automatic correction of photos in PhotoPerfect Express is as easy as shelling pears - just open a folder with photos, specify a photo (if necessary, you can rotate it) and select the optimization algorithm whose processing result turned out to be the best (Fig. 3). Of course, you first need to view the results for each of the algorithms, which can be done by simply clicking on the buttons with the names of the algorithms and watching the photo change, or by calling up the results comparison window (Image Optimization ® All at once), in which the photo will be presented in six versions: original and five transformed. The resulting images are saved in JPG, BMP, TIF or PNG formats and can be sent for printing in popular formats (9x13, 10x15, 13x18, 20x25, etc.).
Rice. 3. Photo optimization using the Xe847 algorithm in PhotoPerfect Express
Optimizing images in batch mode in PhotoPerfect Express is theoretically possible, but in practice only commercial users will be able to use the corresponding tools, since it requires the purchase of the Batch and More batch processing module, which not only allows you to optimize hundreds of photos at once, but also provides access to cropping functions photo and resizing it.
Ashampoo Photo Optimizer 5.5
Developer: Ashampoo GmbH & Co. KG
Distribution size: 51.2 MB
Work under control: Windows XP/Vista/7/8
Distribution method: https://www.ashampoo.com/ru/rub/fdl)
Price: RUR 299.99
Ashampoo Photo Optimizer is a convenient program for quickly correcting unsuccessful photos in batch mode or one at a time. It automatically analyzes the image and makes the required adjustments to color, brightness and contrast, and also “stretches” shadows and sharpens images. As a rule, as a result of such transformations, visually the pictures become much more attractive, they turn out to be brighter, more contrasting and expressive; This is especially noticeable in darkened and faded photographs, photographs taken in poor lighting, etc. However, there are exceptions; in our case, for example, the program sometimes failed to properly adjust the color balance. Ashampoo Photo Optimizer also provides tools for manually processing images - you can rotate and flip images, crop them, level the horizon, eliminate red-eye and perform color correction. Additionally, it is possible to apply simple effects to photos (sepia, aging, blur, etc.) and introduce watermarks into them.
Automatic improvement of images in the program requires a minimum of effort from the user - you just need to open the folder with images and click on the “Optimize” button (Fig. 4). When manually adjusting color, the brightness, contrast, hue, saturation, and gamma values are adjusted using sliders. Processed photos are saved in JPEG formats, BMP, PNG, TGA or TIFF; You can send photos by email, publish them to Facebook and Picasa web albums, set them as desktop wallpaper and print. You can optimize in one click in Ashampoo Photo Optimizer not only one photo, but also all images in a folder at the same time.
Rice. 4. Enhance your photo with Ashampoo Photo Optimizer
SuperEasy Photo Booster 1.1
Developer: SuperEasy GmbH & Co. KG
Distribution size: 8.31 MB
Work under control: Windows XP(SP 1)/Vista/7/8
Distribution method: shareware (seven-day demo version - https://www.supereasy.net/en/usd/dld/0008/SuperEasy-Photo-Booster/)
Price:$19.95
SuperEasy Photo Booster is a very simple utility for automatically improving the quality of photos. The program recognizes those areas of the photo that may look better and optimizes them automatically, adjusting the brightness, saturation and contrast of the image, setting the correct white balance, adjusting the brightness in light and dark areas. The result is approximately the same as in the case of image processing in PhotoPerfect Express using the RGBMax optimization algorithm.
To correct one image, just open it and, if necessary, change the optimization level (Fig. 5); in case of batch processing, a folder is specified instead of a file, in addition, you need to configure the conversion parameters and then start the process. The resulting images are saved in JPG and BMP formats.
Rice. 5. Automatic photo correction in SuperEasy Photo Booster
Comprehensive solutions for image processing
There are many solutions for photo processing on the market, including various types of photo editors and photo organizers. The functionality of such programs, as well as the complexity of their development, can be very different. It makes sense for advanced amateur photographers to pay attention to fairly serious photo editors Adobe Photoshop Elements and Corel PaintShop Pro, beginners are wiser to choose easier-to-use tools, such as the Home Photo Studio program or the Picasa photo organizer.
Any of these solutions provides a traditional set of features for conveniently managing photo collections and editing images. In terms of editing, not only basic operations are available (resizing photos, rotating, cropping, etc.), but also more complex actions with the connection of a wide range of tools for technical (changing the angle, eliminating optical and perspective distortions, correcting incorrect exposure settings, enhancing image sharpness, correcting poor color rendering, etc.) and artistic retouching (applying effects, applying frames, etc.). Also, these solutions provide one or another toolkit for automatic photo correction. It is not difficult to optimize images with its help, although in any case you will have to pay attention first certain time to familiarize yourself with the selected application (especially Adobe Photoshop Elements and Corel PaintShop Pro). However, the results of auto-correction in such solutions, with the possible exception of the product from Adobe, are not as impressive as when using specialized programs for improving images.
Adobe Photoshop Elements 12
Developer: Adobe Systems Inc
Distribution size: 1.08 GB
Work under control: Windows XP(SP3)/Vista(SP2)/7/8; there is a version for Macintosh
Distribution method: http://www.adobe.com/downloads/)
Price:$99.99 (Adobe Photoshop Elements 11 in the Allsoft.ru online store from RUB 2,121.52)
Adobe Photoshop Elements - a comprehensive organization and editing tool digital photos. The application includes two modules: an organizer and a graphic editor, the latter is a simplified version of the famous professional graphic editor Adobe Photoshop, aimed at amateur photographers. The built-in organizer lets you import, manage, view, and search photos and video clips (you can organize your photos by people, location, and events), and provides simple ways for display (creating photo albums, wall gift calendars, postcards, etc.) and online photo sharing. The graphic editor includes a traditional set of tools for this kind of solutions (brush, pencil, gradient, etc.), can work with selected areas and masks, supports layers (including adjustment layers and fill layers) and includes an extensive library of effects.
The graphic editor is designed for detailed correction of photographs and can work in one of three modes: quick Quick, controlled by Guided (with the output of recommendations that simplify the application of operations) and in Expert mode. The tools for quick automatic correction that are of interest in this article are available in fast mode. First of all, this is the so-called “smart correction” Auto Smart Fix, with which, with one click of the mouse, you can adjust the color balance and improve the display of shadows and light areas, and therefore the overall appearance of the image as a whole. The result of such a correction is usually quite impressive (Fig. 6). IN this mode Tools are also available for auto-correction of Auto Levels (adjusts the overall contrast of the image and can affect its color), Auto Contrast (adjusts the overall contrast of the image without affecting its color), Auto Color (provides adjustment of saturation and color shades - Fig. 7) and Auto Sharpen sharpness (provides increased detail). In addition, the “quick” mode has tools for red-eye removal, teeth whitening and stain removal, although these operations are performed manually.
Rice. 6. Smart Adjustments in Adobe Photoshop Elements
Rice. 7. Automatically adjust saturation in Adobe Photoshop Elements
As for the batch mode, Adobe Photoshop Elements provides the ability to process multiple files (File ® Process Multiple Files), during which images can be improved (the Quick Fix panel is responsible for the corresponding operations - Fig. 8) and, if necessary, supplemented with watermarks. Also, with batch processing, it is possible to automatically rename files, reduce their size and convert.
Rice. 8. Batch image correction in Adobe Photoshop Elements
Corel PaintShop Pro X6
Developer: Corel Corporation
Distribution size: 237.5 MB
Work under control: Windows XP/Vista/7/8
Distribution method: shareware (30-day demo - http://www.corel.com/corel/category.jsp?cat=cat4130131&rootCat=cat3520071)
Price:$99.99 (Allsoft.ru version of Corel PaintShop Pro X5 from RUB 3,165.94)
Corel PaintShop Pro is a comprehensive solution for organizing and processing images, designed for a wide range of users. This decision includes an integrated organizer as well as a graphic editor. The organizer provides organization and management of a photo collection (supports facial recognition technology and linking pictures to a map manually or based on GPS data), as well as the creation of stylish photo projects (photo albums, collages, postcards, calendars, slideshows, etc.) with the ability to publish them on YouTube , on Facebook or Flickr. In turn, the graphic editor supports layers, masks and alpha channels and comes with large sets of gradients, masks, fill patterns, textures, frames, tubes, shapes and brushes. It brings together a wide range of photo enhancement tools, as well as multiple framing options, an impressive array of built-in effects and filters, and naturalistic Art Media Tools.
Corel PaintShop Pro offers three workspaces: Manage, Adjust, and Edit. The first allows you to view, organize and search for photos; the Adjust and Edit workspaces provide the ability to edit pictures using the built-in graphic editor - both, among other things, also provide tools for automatic correction. These are the One Step Photo Fix (one-step photo correction) and Smart Photo Fix (intelligent photo correction) functions. The One Step Photo Fix function is responsible for adjusting exposure and white balance, and using the Smart Photo Fix function, the level of brightness, shadows, highlights and saturation is adjusted automatically or by connecting sliders. The results of such correction can be different - sometimes photographs visually look noticeably better than the original ones, although, in our opinion, they are often too bright (Fig. 9). In other cases, especially when processing images taken in bright sunlight and having very pronounced areas of light and shadow, the resulting images are not at all pleasing to the eye. So it all depends on the source material. As for batch processing, the functionality provided in this plan only allows you to rename and convert images.
Rice. 9. “Intelligent” auto photo correction in Corel PaintShop Pro
"Home photo studio"
Developer: AMS Software
Distribution size: 57.35 MB
Work under control: Windows XP/Vista/7/8
Distribution method: shareware (10-day demo version - http://amspark.ru/HomeStudio.exe)
Price: from 690 rub.
“Home Photo Studio” is a simple editor for processing pictures. The program includes minimum set tools for working with photos and is aimed at beginner amateur photographers. With its help, you can crop pictures and level the horizon on them, change brightness and contrast, adjust color balance, etc. In addition, you can apply frames and masks to images, add shadows and a three-dimensional outline, and create postcards and calendars based on images.
Automatic correction tools built into the program (menu Image® Improvement catalog or the use of appropriate scripts) allow you to eliminate the most typical defects - improve photos that are too dark or, conversely, too light, make photos with faded and dull colors brighter, etc. As a result of auto-correction, images often look really better (Fig. 10). Batch processing of files is supported, and during this process, along with renaming and converting files, it is possible to apply scripts from the “Photo Enhancement” group to them.
Rice. 10. Automatic shadow correction in the “Home Photo Studio” program
Picasa 3.9
Developer: Google
Distribution size: 14.3 MB
Work under control: Windows XP/Vista/7
Distribution method: freeware (http://dl.google.com/picasa/picasa39-setup.exe)
Price: for free
Picasa is a popular photo organizer integrated with Picasa web albums. The program combines tools for cataloging photographs (based on albums and “People” collections) and publishing them (creating photo collages, burning photos to a CD, publishing in Blogger, etc.), viewing and simply editing photos. Built-in editing tools allow you to resize images, rotate them, crop them, and also perform a number of image correction operations (removing red-eye, adjusting brightness, contrast, etc.). It is possible to apply filters and effects.
The simplest auto-correction is implemented in the program, although to a minimum. These are the “I’m Feeling Lucky!” functions. (provides color and contrast correction), “Auto Contrast Correction” and “Auto Color Correction”. results automatic optimization images can be quite satisfactory (Fig. 11), but more often they are not pleasing to the eye, although some positive changes in the images usually take place. As for batch processing, in Picasa in batch mode you can only export images to a folder with their renaming and resizing.
Rice. 11. Successful use of the “I’m feeling lucky!” function in Picasa
Conclusion
If you are not eager to delve into all the details of image correction technology and are limited in time, then you cannot do without software tools for automatic image optimization (after all, you still want your photos to look more attractive). By connecting one of the solutions with similar functionality to your business, you can easily improve the quality of your photos without any problems. Moreover, in a minimum amount of time, even with a large number of images in case of batch processing. Another situation is also possible (however, subject to appropriate user training) - mass processing ordinary photos (vacation photos, from a party, etc.) with tools for auto-correction, along with manual finishing of individual photos that are outstanding, in the user’s opinion.
As for solutions for quickly improving the images taken, in our opinion, it is preferable to use highly specialized programs that provide higher quality optimization and are more convenient for solving this specific problem than complex ones software products for image processing.
Image correction in Photoshop
Sofia Skrylina, teacher at the Art training center, St. Petersburg
CompuArt No. 12’2011 discussed methods for diagnosing color shifts and some Photoshop tools for image color correction. In this issue, we will continue to remove color shift using other tools, and also look at situations when it is more appropriate to use the Lab model instead of the RGB model.
Options
Dialog window Options(Variations), in addition to removing color shift, allows you to adjust the tonal balance of the image. At the top of the window there are two thumbnails - the original image and the result of the adjustment. Below are examples of correction; to apply a specific option, you just need to click on its thumbnail (Fig. 1). Using the slider, you can set the accuracy of the correction, and using the switches, you can change the saturation of the image or the correction area: Shadows(Shadows) Midtones(Midtones) Sveta(Highlights).
If the window is reapplied, you must reset it before making adjustments. previous settings by clicking on the original thumbnail.
This window is called by the command Image(Image) -> Correction(Adjustments) -> Options(Variations). In Fig. Figure 2 shows an example of eliminating excess red color using this window.
Rice. 2. Example of removing color shift using the Options dialog box (on the left is the original image)
Applying a Dialog Box Choose color
Team Choose color(Match Color) allows you to remove color shift in one image based on another image. It is used when it is necessary to process a series of photographs taken under the same conditions. In this case, it is enough to balance the colors in one image and process the rest with this command, taking the image with the color shift removed as the source. This command It also turns out to be useful for balancing the colors of different images combined in one project, so that you can use the same colors that would coordinate well.
To match the colors of two images, you must perform the following manipulations:
- Open both files in Photoshop, go to the window of the photo that is subject to correction (Fig. 3).
- Run command Image(Image) -> Correction(Adjustments) -> Choose color(Match Color).
- From the dropdown list Source(Source) select an image whose colors will be used to replace the colors in the color-shifted photo (Fig. 4).
- Set correction parameters:
- using the slider Luminosity(Luminance) — brightness of image pixels;
- via the slider Color intensity(Color Intensity) - color saturation;
- using the slider Let loose(Fade) — partially restore the original colors of the image;
- when checking the box Neutralize(Neutralize) The program will try to determine which shades of the image were neutral and keep them that way. This operation does not correctly identify a neutral color in all cases.
The result of the correction and the original photograph are shown in Fig. 5.
Rice. 5. An example of eliminating excess red color using the Match Color dialog box (on the left is the original image)
Quickly adjust color shift
In addition to tools that have a large number of different settings, Photoshop offers quick adjustment tools. In relatively simple situations, they will help you get a satisfactory result fairly quickly. Let's look at tools for automatic color shift correction.
Auto-correction tools
Automatic color correction is performed in the dialog box Levels(Levels) or Curves(Curves) by clicking the button Auto(Auto), and its setting is in a dialog box that opens by clicking on the button Options(Options), - fig. 6.
For color correction, you can use three pipettes: black, gray and white. If the image contains areas that should have a neutral color, then use a gray eyedropper. To determine the black and white points, black and white pipettes are used, respectively. To use them, you need to select the desired eyedropper and simply click it on the area that should be gray, black or white.
Eyedroppers can be used in conjunction with sliders in a dialog box Levels(Levels) or dots in the dialog box Curves(Curves). First, the color shift is partially removed using eyedroppers, and then more subtle color and tone corrections are carried out.
In Fig. Figure 7 shows an example of eliminating color shift using a white eyedropper. The click was made on the cloud located to the right of the dome of St. Isaac's Cathedral.
Rice. 7. Eliminate color shift and brighten the image using a white eyedropper (on the left is the original image)
In addition to levels and curves, auto-correction can be performed using the command Image(Image) -> Automatic color correction(Auto Color). So, in Fig. Figure 8 shows an example of image correction of the Kunstkamera building.
Rice. 8. Eliminate color shift using the Automatic color correction command (on the left is the original image)
When comparing the obtained result with Fig. Figure 2 shows that the result of auto-correction is closer to reality - it contains less blue color than when using the dialog box Options(Variations). At the same time using the window Options(Variations) the water took on a bluish tint, making the photo look like a postcard. In any case, the choice is up to the user!
It should also be noted that a tool appeared in Photoshop CS5, which allows you to add vibrancy and shine to a photo by increasing detail and glowing edges. This is the dialog box HDR Toning(HDR Toning), which is in the menu Image(Image) -> Correction(Adjustments). It allows you to process a photo at the final stage of correction. So, in Fig. 9 result obtained in the window Options(Variations), adjusted in the window Toning HDR(HDR Toning).
Using the Dialog Box Hue/Saturation
Dialog window Hue/Saturation(Hue/Saturation) is not intended for color balancing of the image. It applies to images that do not have a color shift! But it turns out to be indispensable for increasing or decreasing the saturation of the image, which is adjusted with the corresponding slider (Fig. 10).
Moreover, this window allows you to influence certain colors of the image. So, in Fig. 11, after a general increase in saturation, the sky was processed by affecting only the cyan and blue colors. During the correction, brighter and rich colors Images.
Rice. 11. The result of increasing image saturation in the Hue/Saturation window (on the left is the original image)
Image correction in Lab mode
In the Lab color model, brightness is completely separated from the image, so tonal correction only requires influencing
to the brightness channel, and for color correction - to color channels a And b. It should be noted that the Lab model has a wider color gamut than RGB, so you can painlessly convert from RGB to Lab and back as many times as necessary.
Tone correction in Lab mode
Before proceeding with the correction, you should convert the image to the Lab color model by running the command Image(Image) -> Mode(Mode) -> Lab. In Fig. Figure 12 shows an image of the dome and its histogram, which shows that it is necessary to increase the image contrast.
To increase contrast, most tone correction tools are used, except dialog boxes Exposition(Exposure) and HDR Toning(HDR Toning). In Fig. Figure 13 shows an example of using the dialog box Levels(Levels), correction was carried out only in the channel Brightness(Lightness). As you can see, now you need to increase the saturation of the image.
Increasing image saturation in Lab mode
To increase the saturation of a photo in the dialog box Curves(Curves) it is necessary to change the angle of inclination of the straight line in the channels a And b. In Fig. 14, to increase the saturation of the dome photograph in both color channels, the straight line angle is increased by one amount.
Rice. 14. The result of increasing saturation by increasing the angle of inclination of the straight line in both color channels of the Lab model
Note that color correction in the Lab model produces much less noise than, for example, using the tool Hue/Saturation(Hue/Saturation) in RGB model. So, in Fig. Figure 15 shows the result of increasing the saturation of a photograph of a landscape already familiar to us. The photo on the left is processed in the dialog box Hue/Saturation(Hue/Saturation) in the RGB model, which produced noise in the sky area. In this case, we had to additionally process parts of the image using tools Blur(Blur) and Finger(Smudge) to remove multi-colored pixels (see Fig. 11). In Fig. 15 (right) the same photo was corrected only in the color channels of the Lab model in the window Curves(Curvers). As you can see, the correction did not create any noise.
In some cases, the Lab color model is convenient to use for recoloring an image, as described in CompuArt No. 4’2011.
So, Photoshop provides quite a lot of tools for color and tone correction, the choice of which depends on the specific situation. It is better to carry out correction using several tools in order to then choose the best result.
The article was prepared based on materials from the book “Photoshop CS5. The most necessary" by Sofia Skrylina
Many functions in professional raster editors correct defects in images, but color correction has never been considered easy. Automatic correction tools eliminate routine work, leaving only the final operations to the person.
I’ve been working with Photoshop for a long time, so I was skeptical about the news that some developer had released the next version of a filter that automates the process of correcting colors in an image. But curiosity won out and I decided to try it. I downloaded the demo version and tried to understand how such software could be useful for beginners and how it would benefit professionals. Thus was born a review of automatic image correction programs.
I foresee the objection of skeptics - no program can completely replace human labor. But even professionals can get rid of routine: it’s convenient to see the result of several adjustments at once (in the best packages there are up to 7-8 parameters, some can be turned off and you can evaluate the difference). Other programs allow you to selectively influence selected areas of the image (usually limited to three standard ranges: Shadows, Midtones, Highlights and their combinations). In Photoshop, unfortunately, simultaneous viewing of options is only possible in the Variations operation, but the limited settings reduce the practical benefit to zero.
But for less experienced users, when working with household digital photos, such software allows two or three mouse clicks to get a completely acceptable result. In fact, in Photoshop there are about a dozen functions for controlling image parameters (Image/Adjustments), many of them have an abyss of adjustments. If you consider that one operation is often not enough (usually the process takes 2-3 stages - correction of tonality, color balance, increasing clarity, and each can take several steps), then the means of automatically correcting the basic image parameters will become a real lifeline.
Human Software Autocorrect
Human Software does not shine with developments that are popular with designers - all products are aimed at beginners who from time to time need to “build” something at an amateur level. As a result, Autocorrect is a simple utility for quickly correcting colors in images (the first one is available and, apparently, latest version). Features include increasing the clarity of photographs, removing moire and color correction (the original mechanism gives good results). In the filter window, you can control the redistribution of tones (similar to Curves in Photoshop) in the composite image and separately in each channel. The speed of action is highly commendable.
Auto F/X AutoEye 2.0
 |
| It's just a pleasure to work with such a program |
Since 1994, Auto F/X has been developing various modules for raster editors (two DreamSuite sets, DreamSuite Gel and Photo/Graphic Edges). AutoEye Available as a plug-in and standalone application. The main emphasis in the current second version was on the appearance - now it is in a fashionable aquatic interface style.
All controls are divided into three groups: Enhance Controls (removing artifacts), Color Controls (color correction itself) and Creative Controls (special effects). The first contains tools for equalizing color balance in the image (Remove Color Cast), restoring details (Rebuild Detail), noise suppression (Smooth Noise) and moire (Anti-Moire). Settings from the second affect the redistribution of colors in the image (Saturation, Hue, Contrast, Brightness). An interesting setting is Tonal Range, which increases the depth of tone without increasing contrast or changing the overall color balance. You can add additional effects such as blur (types known from Photoshop: Motion, Radial, Zoom). The module gives very decent results, but how relevant its special capabilities are is a moot point. The quality of AutoEye, assessed by removing excess colors (color cast) in automatic mode, turned out to be the highest compared to other filters in the review.
A special feature of the filter is Memory Dots, which remembers the current results for the duration of the workflow. The necessary parameters are recorded in the form of Presets.
iCorrect EditLab 3.0
The developments of Pictographics are little known, which, however, does not in any way detract from their significance. EditLab Possessing the most ascetic interface and the minimum number of settings among similar developments, it brings quite tangible practical benefits.
Correction is possible in fully automatic and manual modes. In the latter case, you need to manually determine the gray level in the image using a standard eyedropper, and then the white and black levels (this operation is optional). Based on this data, the utility creates a corrected image. In automatic mode additional settings not provided - the Auto button will do everything itself. The same window displays the brightness, contrast and saturation parameters used during auto-correction (you can edit them manually if desired). iCorrect coped well with the task of restoring the color balance, and no other product showed such radicalism (the filter almost completely suppressed the “redness” in the image). But the developers, apparently, decided to leave more advanced operations (moire suppression, clarity enhancement) for us to decide on our own.
Among the original settings, I would like to note the automatic binding of the specified areas to three specific color ranges (Skin, Foliage, Sky). It looks like this: let’s say you need to correct your complexion. First, using the eyedropper, we “clip off” the places that should have a flesh color (to make it easier to determine which colors fall into the selected range, turn on the Show sampled region parameter in Preferences), and then click Skin. The utility adjusts all colors that fall within the range to the standard skin color values of Europeans. A troublesome task turns into a simple operation. The same applies to adjusting the color of foliage and sky. If the result is not satisfactory, you can reconfigure the default values and save them for recall (Save Color Circuit). Expand the program's capabilities for adjusting image brightness and saturation.
Intellihance Pro 4
The Extensis company does not need any special introduction - its products have found recognition among the design and layout fraternity. The pioneer of this trend, the Intellihance filter, has been popular for a long time. Almost since the days of Photoshop 4.0, its position has remained unshakable, and today it is the most advanced tool for adjusting images. It has three main modes - Intelligent Adjustments, Fine Tune and Power Variations.The first is a powerful tool for automatic complex image correction. The asset includes 8 adjustments, covering all frequently used functions: Descreen, Dust&Scratches, Contrast, Brightness, Saturation, Cast, Sharpness, Despeckle. Each has several predefined values: for example, Auto, Newspaper, Magazine and Fine Art are available for Despeckle, which guarantees the removal of moire that occurs when scanning any materials, and to align the color balance in the image, the Purify Gray Balance, Remove Cast and Aggressive Removal settings have different effects. To facilitate the basic tasks of the operator, all settings are organized into 25 predefined sets and placed in the Photoshop menu as a separate Extensis item. Of course, you can create your own settings and also have accelerated access to them.
The starting point for using Intellihance is to set the Quick Enhance full automatic correction mode, the settings of which, according to the developers, eliminate most problems. After this, you can compare its quality with the result of other settings aimed at solving specific problems (their names speak for themselves). Accordingly, the quality of the program in such a semi-automatic mode depends on how accurately the the best option corrections. It seems to me that understanding them is very difficult even if you have experience in color correction, and the procedure for correcting an image can come down to automatically going through all the available settings. I quickly got tired of this and preferred to manually adjust only those parameters that I considered necessary.
For manual correction, the Fine Tune mode is used, in which image parameters are controlled using graphs and sliders (like those found in Photoshop), which gives additional flexibility. The result is in the same window. The disadvantage of this mode is the small size of the graphs, which does not allow you to manage them with the same degree of accuracy as in Photoshop.
Power Variations is a powerful analogue of the Variations function known from Photo-shop. It simultaneously displays up to 25 variants of the original image on the screen, while the basic one can be pre-processed (many ready-made settings are offered for different cases). The step of changing the parameters varies widely (Preferences). To control color, there is a special panel with information in the form of RGB, brightness and contrast.
A recent update (4.1) added support for Photoshop 7 and Mac OS X.
Intelligent Automation
Of all the modules reviewed, Intellihance Pro seems to be the clear favorite, followed by Auto Eye, the quality of which is also high. It is difficult to single out anyone among the rest. After testing on various types of images, I was of two minds.Not a single module in the automatic correction mode showed truly high-quality results with all images (it coped well with some, but with others the processing left much to be desired).
Even on similar tasks (removing a dominant color in different photographs), the same product gave noticeably different results. There are many explanations for this, but I would like to focus on a practical conclusion: not a single program, even the most intelligent, can replace human experience. Consequently, such utilities can only be used under heavy workload, for processing many images of the same type, and only at the first stage of correction, and the final refinement must be done manually. Where would we be without them?
About the author: Mikhail Borisov([email protected]) - writes reviews for Publish software and useful tips on prepress and web design.
Autocorrect
Developer: Human SoftwarePlatforms: Mac OS, Windows
Flaws: very few features, everything is implemented only at the most basic level.
Summary: The filter is recommended only for beginners and the laziest.
Demo version: www.humansoftware.com
Price:$60
AutoEye 2.0
Developer: Auto F/XPlatforms: Mac OS, Windows
Advantages: very decent quality of work, beautiful interface.
Flaws: It is not always intuitively clear what moving the engines will lead to; the filter noticeably “slows down”, the only thing that can save it is turning on the Proxy (Preferences) rough rendering mode.
Summary: A tool worth having in your collection.
Demo version: www.autofx.com
Price:$130
iCorrect EditLab 3.0
Manufacturer: Pictographics InternationalPlatforms: Mac OS, Windows
Advantages: good quality of work with a minimum of settings; all elements are functional, there is nothing superfluous.
Flaws: There are no relatively complex operations (moire removal, sharpening).
Summary: The program does not claim to be of a professional level, but for many tasks its capabilities are quite sufficient.
Demo version: www.picto.com/editlab
Price:$100
Intellihance Pro 4
Developer: ExtensisPlatforms: Mac OS, Windows
Advantages: a colossal selection of parameters gives greater freedom and flexibility in work; high speed image processing.
Flaws: The number of parameters can also be considered a disadvantage. The settings are not easy to understand (they are clearly not for beginners), and the description of the effect does not always coincide with the effect it produces (for removing obvious excess in the test image, not a single setting from the Cast setting had the expected effect). The utility is expensive (for comparison: Photoshop 7 costs a little more than $600).
Summary: the most powerful utility of all those considered, with some experience it will be useful even to professionals in the field of correction (the Pro in the name says so). During frequent promotions, the product is sold at half price.
Price:$200
Photoshop can do it all
Photoshop provides a rich arsenal of manual color correction tools, allowing you to control the slightest nuances of color in an image. Typically the procedure consists of three stages:
- tonal correction (setting white and black, determines the range of colors);
- color balance correction (removing the dominant shade);
- increased clarity (increased level of detail).
Let's start in order. Stage one - setting the brightness. The simplest operation to redistribute pixel brightness is Levels. The top chart displays the current distribution of brightness in the image, and the bottom chart shows the entire available range - from 100% white to 100% black. Three sliders are responsible for the darkest, neutral and brightest points in each channel or composite image. When you move the first slider to the side light colors the contrast of the image decreases (the darkest areas become lighter), the same thing happens when you move the slider responsible for the brightness of the lightest point towards dark tones (shift to the gray area). Intermediate brightnesses are determined by linear approximation. By changing the position of the neutral point, you can further influence the redistribution of dark and light areas.
A more powerful operation is Curves. Unlike Levels, it changes the brightness of pixels more flexibly: the uneven law is often used to increase contrast in the image. To do this, the graph is given an S-shape: all pixels with brightness less than 50% are forcibly darkened, and those more than 50% are brightened. If you move only the extreme points on the chart, you will get the same effect as when using Levels.
The second stage is adjusting the Color balance. One of the most popular color correction operations is designed to redistribute colors in an image (the main purpose is to remove the dominant hue). It is advisable to enable the Preserve Luminosity option, which preserves the brightness range.
There are other ways to change the basic parameters of an image (hue, saturation, brightness): separately in each of the main color ranges - the Hue/Saturation or Selective Colors operation; directly selecting a color using the eyedropper - Replace color. By specifying the range of capture of adjacent shades, you can change the color parameters within a wide range.
To automatically correct certain image parameters, Photoshop has a built-in set of functions (Image/Adjustments) - Auto Levels, Auto Contrast, Auto Colors.
Auto Contrast increases the brightness range of an image, setting the darkest point to 100% black and the brightest point to 100% white. The intermediate values shift, making dark areas darker and light areas lighter. Since the operation is performed on a composite image, no color shifts (imbalances) occur. Auto Levels does the same thing, but analyzes each channel individually. Accordingly, color shifts are almost always guaranteed. But the Auto Colors operation restores the lost color balance, and, in principle, it alone is often enough for quick color correction of acceptable quality.
Before you decide to purchase additional correction software, try all the capabilities of Photoshop first - it’s not for nothing that it is called the flagship of work with raster images.
Dealing with artifacts after scanning
As a rule, scanned images require, in addition to color correction, removal of dust, scratches, moire, and sharpening. There is a whole arsenal of tools for this in Photoshop (Noise/Dust and Scratches, Despeckle, Unsharp Mask), but for high-quality results you need to first prepare the image - accurately determine the area of influence of the filter.
The Despeckle filter removes moire that occurs during scanning. But sometimes its one-time use is not enough. Then the filter is reused or Noise/Median is applied with a Radius value of 1-2 pixels.
In principle, Photoshop can deal with dust and scratches (Dust and Scratches), but often the quality of its work leaves much to be desired (it noticeably blurs the details in the image). That's why small parts It is advisable to protect it from the effects of the filter. Considering that they are most perceived by the eye as changes in brightness, and not color, we will work in the LAB (Image/Mode) color model. We go to the brightness channel L, duplicate it and use the Find Edges filter to highlight sharp changes in brightness (to make them appear even sharper, the contrast can be increased). We save the channel as an image mask and calmly apply the Dust and Scratches filter - the mask protects sudden changes in brightness from the influence of the filter, which is what was required.
Image Doctor
Among third-party manufacturers offering solutions to improve the quality of photographs, I would like to note the development of Alien Skin. The company is well known for its generation filters (EyeCandy, Xenofex, EyeCandy 4000, Splat!) for various raster packages. Recently, developers have turned their attention to the problems of image correction and now offer Image Doctor - a collection of four filters: Smart Fill, Scratch Remover, Spot Lifter and JPEG Repair. In principle, they do not fall under the category of tonal correction tools, since their direct work is “worn out” images.
The first of them is used for invisible retouching of large areas of the image, but for an acceptable result on a complex background it will have to be applied several times. Scratch Remover will remove small artifacts found in scanned images: scratches, fold defects. But it works extremely slowly and therefore is unlikely to compete with the usual method of cloning using the Stamp tool in Photoshop. If the image was compressed with a high degree of JPEG compression and the loss in clarity is very noticeable, try using JPEG Repair - it restores the original quality of the image (and although the main effect is achieved by the Blur Edges parameter, the result is still definitely better Smart Blur from Photoshop - the first one preserves more fine details). The filter removes the characteristic blocky structure of “overcompressed” images, only slightly reducing the clarity of small details.
Of all the filters in the collection, Spot Lifter is the most interesting. Its task is to nullify contaminated areas, smoothly transferring them into the background image. The principle of operation is based on shading the problem part (feather) with partial duplication of the border area inward. The quality of the filter is average. You can get no worse results by skillfully using the standard Photoshop set (in particular, the Healing Brush).
The cost of the filter is $130. The capabilities of Image Doctor do not justify the price, which seriously reduces its practical value.
Still Photoshop?
As seen in example Image Doctor, most of the defect reduction tools, for which you will have to pay extra money (as well as tools for automatically correcting colors in images), are quite implementable using standard Photoshop tools. Powerful tools appeared in the seventh version of the editor - these are Healing Brush and Patch.
Basically, Healing Brush is a more developed analogue of the well-known Clone Stamp. The tool, as it were, “dissolves” the cloned area in the edited place, exactly repeating all the features of the latter (texture, hue, brightness). This is convenient even for retouching fairly large areas of the image. Available adjustments include brush size and blending mode.
Patch works only on the selected area, using it as a cloned sample or retouched area. Both tools cope well with various artifacts (creases in folded areas, stains and unwanted writing on photographs).
There are several ways to remove the unwanted effect that occurs with a bright flash and insufficient lighting. Regardless of the choice, it is useful to first create a copy of the document (Image/Duplicate) and in it increase the size of the adjusted area to 100 or even 200%. In order to check how they look in the general context when making changes, place the window with the duplicate so that it does not overlap the original document.
The easiest way to suppress is the Sponge tool. Once you've chosen your brush size and hardness, simply brush over the areas with a red tint. Their saturation will decrease, and the pupil will become a more natural color. The procedure is repeated several times.
The second way is to manipulate the layer blending modes. First, “pipette” the color of the pupil with an eyedropper and on a new created layer (Layer/New) use a brush to outline the areas with a red tint. Set the active layer's blending mode to Saturation and experiment with its transparency. If the pupil looks unnatural, duplicate the active layer and set its blending mode to Hue. By adjusting the transparency of the layer, you can achieve a completely believable result.
Image brightening
Duplicate the layer and set its blending mode to Screen. If the result remains too dark, repeat the operation; if too light, try making the layer partially transparent. To darken overexposed areas, the easiest way is to create a transparency mask for the layer and use a brush of the appropriate size to darken the problem areas. Both operations with layers when adjusting images are standard, and therefore in other cases they can be used without restrictions.
Dimming the image
Duplicate the image onto a new layer and set its blending mode to Multiply. If the result is unsatisfactory, use the already known operation with repeated duplication, changing the transparency and creating a mask.
If the image is faded, you can duplicate the layer and set its blending mode to Soft Light. Further actions are standard.
Increase contrast
In the early versions of Photoshop the contrast was increased only by giving the curve an S-shape in Curves (or using Auto Curves); in the “seven” a new Vivid light mode appeared, which brightens pixels with a brightness of less than 50% and darkens the rest - in general, it gives a similar effect.
Magazines are freely available.
On the same topic:
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In this tutorial we'll show you how to apply selective color correction to a photo, or more precisely, how to convert an image to black and white, but still leave the selected element in color.
And although this effect is extremely easy to achieve in Photoshop program, many are wary of it, because they are not always sure of what they choose the right tools. Most often, people resort to selection tools, and then there are often hiccups. In this tutorial we'll show you how to create this effect without using selection tools. All we need is a simple Black & White adjustment layer, a layer mask and a brush, nothing more!
I'll be working in Photoshop CC, but this tutorial is also compatible with Photoshop CS6.
So, here we have the original photograph, which shows a woman in a red dress.
Original image
And here is the image that we will get after performing all the necessary manipulations. The entire photo will be converted to black and white except for the red dress. Again, we won't resort to using any selection tools.
Final image
You can follow all the steps in this tutorial while working with your own photo. Just select a photo and identify an object that will remain in color, it could be a dress, a flower, a telephone booth, in general, anything. Let's get started already!
Step 1: Black & White Adjustment Layer
Only after opening the program, you will see in the layers panel that the document so far contains only one layer - the Background layer - which is the original image.
We will create the effect using a non-destructive method, i.e. Let's leave the original image untouched and apply selective color replacement using a separate adjustment layer. Click on the New Adjustment Layer icon at the bottom of the layers panel:
Click on the New Adjustment Layer icon
From the list that appears, select the Black & White item:
As the name of this adjustment layer tells us, it is used to convert a color image to black and white. Now let's look again at the layers panel, as you can see, above the Background layer there is now a new Black & White adjustment layer.
Photoshop placed a new adjustment layer on top of the image layer.
We see that the program itself converted our color photo to black and white, using the default settings. We can independently adjust the parameters of the black and white image, which is what we will do now.
Convert to black and white by default.
Step 2. Adjust the settings for converting to B/W
You can find all the controls for the Black & White adjustment layer in the Properties panel. Here you will see six sliders, three of which are responsible for the primary colors (Red, Green and Blue) and the next three for the secondary colors (Yellow, Cyan and Magenta). Move the slider to the left to darken, or to the right to lighten the area of the image that contains a given color in full color.
For example, moving the red slider to the right will cause the area of the image that originally contained red to become lighter. And by moving the blue slider to the left, we will darken the areas that were originally blue. You should not thoroughly memorize the colors of all image elements, since this is easy to understand by moving the sliders. Do you like the result? Yes? Amazing. No? Then keep experimenting with sliders.
Move the sliders to darken or lighten areas of the image based on their original color.
Above the sliders you will find the Auto button. This button sends a command to Photoshop, by which the program itself selects the parameters. Sometimes it works, sometimes it doesn't. But you can always correct the result yourself after using the Auto button.
If you want to compare your black and white version with the color version, simply click on the visibility icon (the eye-shaped icon) in the Layers panel to turn off the visibility of the adjustment layer. By turning it off, you will see your original image. To return to black and white, return the adjustment layer's visibility:
This is what my photo looks like after conversion. On at this stage there is no point in making everything perfect. You will see that we can always return to this point to make any changes.
Corrected black and white version
Step 3: Select the Brush Tool
One of the main advantages of all adjustment layers is the built-in layer with a mask. In this article I will not go into detail about how exactly masks work, but if you are interested, I advise you to find the material and read it. And although the mask is not visible to us in the image itself, we know that it is there because its thumbnail is displayed in the layers panel. Notice that at this stage the thumbnail is filled with white, which means that the adjustment layer is affecting the image layer underneath it.
We can reveal some of our color source image with an adjustment layer by simply painting over the mask with a black brush. Select the Brush Tool from the Tools panel:
Step 4: Select a Soft Round Brush
Click on any part of the open document right click mouse (Ctrl key for Mac) to open the brush settings panel. Then select the soft round brush from the top left corner of the panel. Press Enter (Return for Mac) to close the window.
Select a soft round brush
Step 5: Change the Foreground Color to Black
Photoshop uses the Foreground color as the brush color. Since we need to paint with black using the layer mask, we should change the Foreground color to black. To do this quickly, press the D key. This command instantly sets the original colors for the foreground and background, namely white and black. To change them, press the X key on your keyboard. The foreground color should now be black.
We can see the current colors at the bottom of the toolbar. The foreground color is indicated by the square located at the top, and the background color at the bottom.
Step 6: Paint the inside of the object
To return the color to the selected object, first, arm yourself with a large soft brush and on the layer mask, begin to paint only the inner part with black, without touching the edges of the object. You can change the brush size using the keyboard. Hold down the key ] to increase the brush size, and the key [ , to decrease. To increase brush hardness, hold down Shift along with the key ] , and in order to reduce hardness use a combination Shift+[.
In my photo, I decided to return the color to the girl's dress. I use a large diameter brush to paint most of the object without worrying about the edges. I started from the bottom of the dress.
I then switched to a smaller brush and painted part of the top of the dress, again leaving the edges alone.
Notice that if we look at the layer mask thumbnail, we can see that the areas we painted in the photo are now showing up in black. This is how a layer mask works. The color white is used to indicate the areas of the image to which the effect is applied. The black color on the layer mask indicates areas where the effect is hidden.
Step 7: Paint the edges with a smaller radius brush
To accurately draw the edges of an object, you should first zoom in on the picture. You can also use convenient hotkeys for this. To zoom in on a photo, press and hold Ctrl+Spacebar (Win)/Command+Spacebar (Mac) and click on the desired area of the image. To zoom out of a photo, use the following keys: Alt+Spacebar (Win) / Option+Spacebar (Mac).
To draw finer details in the photo we will need a brush with a smaller diameter. To make the brush smaller, I press the left square bracket key several times. You may have to increase the hardness of the brush; I described how to do this using hotkeys just above.
Very carefully draw the edges of the object with a brush of a smaller diameter.
If you accidentally drive over the boundary of an object, there will be nothing wrong with that. For example, I accidentally drew a finger:
This error is very easy to fix. Press the key X to change the foreground color from black to white. Then use a white brush to paint over the area you touched to get rid of the color. And then press the key again X to return black as the main color and continue working.
I continue to paint around the edges of the dress, zooming in and out and changing the hardness and size of the brush if necessary.
Final result:
Step 8. Make adjustments to the Black&White settings
At this point you may want to adjust the settings of the Black&White adjustment layer. To do this, in the layers panel, go to this adjustment layer and open its settings panel. Adjust the sliders until you achieve the desired result.
Additional step:
Since we only worked with one adjustment layer, we can easily reduce its effect, partially returning the photo to its original colors. To do this, we just need to slightly reduce the Opacity of the layer. You'll find this option at the top right of the Layers panel. I reduced the opacity to 75%:
This adjustment will allow the original colors to show through a little through the adjustment layer that sits on top of the image. Let's compare the Before and After photos again:
And here's the final image with the vibrant red dress taking center stage.
As I already said, you do not need to know how these tools work, but you need to know something else - in which cases you should give preference to one or another tool to get better results.
To make it a little easier for us to understand this issue, let's slightly repeat the theory. As you know, the entire variety of colors displayed on a computer monitor is generated by shifting the three primary colors - red, green and blue.
White color is obtained by mixing red, green and blue in equal proportions and full intensity. Black is the complete absence of all three primary colors. Yellow, for example, is made by mixing red and green. Mix red and blue to make magenta, while green and blue together make turquoise. Apply shifts of red, green and blue in varying proportions and their shades in all possible shades, and you will end up with millions and even billions of colors.
Photoshop mixes these three primary colors using color channels. One channel is for red, another is for green, and the third is for blue. We can find these color channels in the Channels panel, which, by default, is nested in the same stack as the Layers panel. Click on its tab at the top of the panel group to open it:
Open the channel panel by clicking on the corresponding tab.
In the panel we see red, green and blue channels, plus a fourth RGB channel located at the top of the panel. Don't let the RGB channel fool you, it's not really a channel at all. RGB stands for "red, green and blue" and is simply a combination of the red, green and blue channels working together to give us a complete color image.
If you look at the red, green and blue channel preview thumbnails, you'll notice something that might seem a little surprising - these color channels aren't actually in color at all! Instead, each one is a halftone image. In fact, if we look at them more closely, we can see that the black and white image of each channel is different from the other. To preview how each channel looks in the document, simply click on it. For example, I'll click on the Red channel to select it:
Selecting the red channel.
With the red channel selected, the full color version of my image in the document is temporarily replaced with a grayscale version. So what does a black and white image mean when the red channel is active? This is how Photoshop shows the intensity of red in a picture - the brighter the area, the more red is added to the full color version, while darker areas have less saturated red. Areas of pure white in a black and white image have red at its full intensity, while areas of black have no red at all:
Preview of the red channel. Bright areas contain more red than dark areas.
To see what the green channel looks like in the document, I'll click on it in the Channels panel.
This action will temporarily turn off the display of the red and blue channels, showing me only the green channel in the document. Here we see another grayscale image, but it's slightly different from what we saw with the red channel. This happens because the intensity of green in different areas of the photo is naturally different from the intensity of red. Again, the brighter the area, the more intense the green color it is, while the darker areas have a less saturated green. Any areas of pure white have full green intensity, while areas of pure black have no green at all:
Green channel preview. Lighter areas = more intense green, darker areas = less green.
If we now look at a black and white image of the blue channel, it will be just as different from the others and work exactly the same. My photo contains a lot of blue (or any other color that uses blue as its main ingredient), so the blue channel looks overall darker than the red and green channels:
Blue channel preview. The lighter the area, the more blue is involved in mixing the color in the full color version.
So far we've learned that Photoshop mixes the red, green, and blue color channels to produce all the colors we see in an image. Now, based on this, let’s try to figure out which of the three tools under consideration is best for us to use when. Each of the three automatic commands manipulates color channels differently, producing different results. Next, I'll briefly describe how each of them works before we look at them in action.
The Auto Contrast tool is the most basic and straightforward of the three discussed in this tutorial. When we select it, Photoshop analyzes a composite of all three color channels (in other words, it treats all three as if they were one black and white image) and simply converts the dark pixels to pure black, brightens the light pixels to pure white, and redistributes all other tonal values in between. The result is an image with improved overall contrast. It's important to note that because it treats all three color channels as one composite image, Auto Contrast does not change the colors in the image. It simply enhances overall contrast, making it a good choice for images that don't suffer from any color issues.
Auto Tone is similar to Auto Contrast in that it also darkens dark pixels to pure black, brightens light pixels to pure white, and redistributes all other tonal values between them, but it has one major difference. It does this not based on three channels mixed into one, but based on each channel separately, which means that the red, green and blue channels will also be adjusted individually. We know that Photoshop uses the brightness values in each individual color channel to determine how much of each color to mix in the full color version, so by changing the color channels independently of each other, we will change the colors in the full color photo because... The brightness values in the channels have been changed. This means that, unlike Auto Contrast, which does nothing more than increase overall contrast, Auto Tone changes the colors in the image at the same time it increases contrast. If an image has an unwanted color cast, Auto Tone may be able to correct it.
Auto Color is similar to Auto Tone. It also darkens dark pixels to black and brightens light pixels to white on a channel-by-channel basis, so that the red, green, and blue channels will be adjusted separately and independently of each other. But Auto Color goes one step further. Instead of simply redistributing all the tonal values between them, it attempts to correct any unwanted color cast by neutralizing the midtones in the image. This usually (but not always) makes Auto Color the best choice for automatically correcting contrast and solving color problems at the same time.
In the next article I will tell you how to correctly and effectively use automatic image adjustment tools.
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