A PNG file is a raster image saved in the Portable Network Graphic format. Each PNG image contains a palette - a set of colors used. To reduce the file size, lossless compression using the Deflate algorithm is used. Used primarily on the Internet as images for web pages. The format was developed to replace GIF, which, in addition to its shortcomings, had restrictions for free use until 2004 software. The new PNG format solved these problems. In particular, it implements support for an 8-bit alpha channel and support for color depths up to 48 bits. While in the GIF format only full transparency is possible and the color palette is limited to only 256 colors (8 bits). However, unlike its predecessor, this format does not support animation. For this purpose, another MNG format was created. IN PNG files It is also impossible to use the CMYK palette, because this format is not intended for professional work with graphics. PNG files can be opened in any browser and almost any image viewing and editing program. IN Windows file with a PNG extension can be opened by double clicking the mouse.

The file extension .png represents a PNG image. Viewing and processing of a raster image in PNG format is possible using the following programs: Microsoft Windows Photos, Microsoft Windows Photo Viewer, Microsoft Paint, Adobe Photoshop CC. Also, the listed programs can convert images, pictures and drawings of this format.

A PNG file can be opened with special programs. To open this format, download one of the proposed programs.

The PNG extension is a file format used to store images without loss of quality. This is the most popular photo format on the Internet, specifically designed for use on the Web.

A file with a PNG file extension is a file Portable Network Graphics. The format uses lossless compression and is generally considered an alternative to GIF. But unlike GIF, PNG files do not support animation.

The PNG format has both grayscale and full-color photographs, and transparent layers are supported. PNG compression is usually better than that, which is used in GIF. JPG is sometimes superior to PNG, but the compression can cause artifacts in images with text or around high-contrast areas.

How to open a PNG file

To open PNG files, you can use any Internet browser or graphics editor. Both Windows and Mac OS platforms have built-in mechanisms for viewing such images.

What is the PNG format used for?

Png Program - Viewer Windows photos the default is often used to open PNG files, since this is the system Windows program. But there are many other ways to view them.

All browsers (eg Chrome, Firefox, Internet Explorer etc.) will automatically view PNG files you open on the Internet, meaning you don't have to download every PNG file you want to view onto your computer. You can also use your browser to open PNG files you already have on your computer using the Ctrl + O key combination. Most of these programs also support drag-and-drop, so you can simply drag the PNG file into the browser to open it.

There are also several offline options for opening such images - these are special graphic editor. A few popular ones - XnView , IrfanView , FastStone Image Viewer , Google Drive , Eye of GNOME and gThumb. To edit PNG files, you can use almost any of the listed programs, applications Paint And Paint.NET, the popular GIMP utility, as well as the well-known Adobe Photoshop.

PNG conversion

Image files can be converted different ways, for example, convert to and from png using various programs and online services. For example, this can be done by the Png editor - Photo Converter.

An image file that is stored in the Portable Network Graphic (PNG) format. Contains a bitmap of colors and uses lossless compression, similar to a .GIF file, but without copying restrictions. Typically used to store web image graphics.

The PNG format (read as png) was created in response to restrictions GIF format, primarily to increase color support and provide a patent-free image format. In addition, while GIF files only support opaque or fully transparent pixels, PNG images can include an 8-bit transparency channel that allows colors to change from opaque to transparent.

PNG images cannot be animated as GIF images. But the associated .MNG format can be animated. PNG images do not support CMYK because they are not intended for professional graphics use. PNG images are supported by most web browsers.

Mac OS X 10.4 and later stores screenshots as PNG files. Ubuntu Linux also stores printed screenshots in PNG format.

MIME type: image/png

Download the program for the format PNG

In this article I want to talk about one very unpleasant feature of Photoshop that appears when saving transparent images in PNG24. Let's take the original image and copy some fragment into PNG24. I did it this way: using the Polygonal Lasso tool, I selected a fragment, copied and pasted it into new document, then saved via Save for Web:

PNG24, 456 KB

As we found out in Part 1, in PNG24 an image is essentially made up of two layers: an RGB layer containing information about the color of each pixel, and an alpha channel containing information about their transparency.

PNG graphic format: processing and viewing

It is logical to assume that in completely transparent areas there should be some one color in order to effectively pack the image. However, this is what Photoshop saved in the RGB layer (I saw this through the Seashore editor):

And the naked eye can see that large fragments of absolutely unnecessary information remain:

If you don’t want to use other editors (for example, I didn’t notice such a drawback in Adobe Fireworks), I suggest a simple way to eliminate this defect in Photoshop. Our task is to replace all information in completely transparent areas with some one color (preferably black, so as not to doubt that these areas will have the least weight in bytes).

1. Open the example in Photoshop and select the image on the layer: Ctrl+click on the small layer image in the Layers palette.

2. Let's switch to quick mask mode (Q key).

3. C using Image→ Adjustments → Threshold we will leave only those mask pixels whose color was black. To do this, drag the slider to the far left position.

4. Exit quick mask mode (Q key) and invert the selection (Select → Inverse or Ctrl+Shift+I). Only completely transparent pixels remain selected.

5. Fill the selected area with black (there are many ways, for example, via Edit → Fill).

6. Invert the selection again and add a mask to the layer (icon in the layers palette).

7. Now we do Save for Web and see how the image miraculously “thinner” by 122 KB.

I repeat once again that all actions are very conveniently recorded in Actions, after which they are performed with one keystroke.

To be continued.

Communicating with my colleagues at various seminars and in the studio, I came to the conclusion that for many the only advantage of the PNG format is the presence of honest translucency. If you search the Internet for information about this format, it is easy to notice that web developers are divided into two camps. The first write about how wonderful this format is, using purely technical data that is incomprehensible to ordinary coders and designers (for example, about the superiority of deflate compression algorithms over LZW), while others leave comments of varying degrees of stupidity about the uselessness of PNG, without even bothering to delve into the essence of the things described in the specification.

Let's try to figure out what advantages this format provides in order to learn how to use them when preparing illustrations for the web.

Let's start with terminology. I assume that most readers use Photoshop and have come across the names PNG-8 and PNG-24. These are not two different formats, but just variations of the same PNG. The format allows you to store three types of images: greyscale (one channel is used to describe the image - white), indexed-colour (a color palette is used, like in GIF) and truecolor (three channels are used - RGB).

The most important advantage of the PNG format is, of course, new compression algorithms. Everyone remembers that GIF effectively compresses only horizontal areas of the same color? You can now forget about this limitation:

GIF, 2568 bytes

PNG-24, 372 bytes

The second important advantage is line filtering (scanline filtering, or delta filters), thanks to which the PNG packer can obtain much more convenient data for compression.

Let's look at an example of how they work. Let's take a 5x5 pixel image with a horizontal gradient and diagram how it can be saved to a file (each number is a unique color).

As you can see from the example, a GIF encoder would compress strings that don't pack well horizontally (because the same colors spread vertically). Here's how a PNG encoder can convert this data:

The number 2 appeared before each line. This is the filter that was applied to the line. In this case, it's the Up filter, which tells the decoder: "For the current pixel, take the value of the pixel above and add the current value to it." In our case it is 0, because the colors of the current and top pixels are not different. And this data can be packed more efficiently if we have a large enough image.

Why did I write Maybe? Because in our idealized case, the following scheme would be more effective:

Filter 1 called Sub is applied here, which tells the decoder: “Take the value of the pixel to the left of the current one and add the current value to it.” In this case 1.

After filtering, all strings (along with filter values) are combined into one sequence, which is then compressed using deflate algorithms (their discussion is beyond the scope of this article).

Let's check the filters:

An attentive reader may notice that filters are applied not to the entire file, but to lines.

PNG file format - what is it?

It means that each the string may have mine filter. It turns out that there can be 5 image heights for filtering one image. In general, the task of a good encoder is precisely to select such filter values ​​at which the file size will be minimal. Unfortunately, Photoshop does not always do its job well, so various utilities like OptiPNG and PNGCrush come to the rescue, which select different filtering methods and data compression strategies in a large number of passes, thereby significantly reducing the volume of some complex images. However, it is worth remembering that these programs do not guarantee a reduction in size for each file, they just try to find the optimal way to encode the data.

Another painful jab at Photoshop is that it does not know how to save images in greyscale mode, that is, it does not know how to reduce the color depth. Here we will again be saved by the above-mentioned utilities, which, if possible, reduce the color depth without compromising the quality of the picture.

PNG-24 (Photoshop → truecolor), 8167 bytes

PNG-24 (Photoshop + OptiPNG → greyscale), 6132 bytes

The advantages of greyscale over truecolor are obvious: for example, white in the first case is written (in the decimal system) as the number 255, and in the second - 16777215.

Now, armed with knowledge about storing data in the PNG format, we can use it in preparing images for the web. More on this in the following articles.

You"re here because you have a file that has a file extension ending in .png. Files with the file extension .png can only be launched by certain applications. It"s possible that .png files are data files rather than documents or media , which means they"re not meant to be viewed at all.

what is a .png file?

PNG files are compressed raster image files usually implemented for visual elements found in a website among other Web graphics. The image content of these .png files consists of index colors integrated by bitmap images, and the lossless digital image compression and encoding specifications that are implemented into these .png files are similar to the compression standards integrated into GIF files. Also known as portable network graphics, the PNG format was developed to lift the limitations of GIF images, in terms of color support and patent licensing. The transparency channel of these PNG files have been improved to implement 8-bit support. CMYK support is not available in these PNG files.

how to open a .png file?

Launch a .png file, or any other file on your PC, by double-clicking it. If your file associations are set up correctly, the application that"s meant to open your .png file will open it. It"s possible you may need to download or purchase the correct application. It"s also possible that you have the correct application on your PC, but .png files aren"t yet associated with it. In this case, when you try to open a .png file, you can tell Windows which application is the correct one for that file. From then on, opening a .png file will open the correct application.

applications that open a .png file

Adobe Photoshop CS6 for Microsoft Windows

Adobe Photoshop CS6 for Microsoft Windows is an image editing and managing software downloadable on Windows computers, namely Windows 7 (without SP and with SP1) and Windows XP with SP3. This software comes with new features and tools for easy, quick, fun and advanced editing of digital images. One feature that makes this program reliable for image editing is the Adobe Mercury Graphics Engine, which is an engine technology that provides faster and high quality performance. Content-Aware tools are new designed features for retouching images with ease as you can crop images without any effect, auto-correct blurriness or wide-angle lens curvatures, remove red eye, and adjust color balance like brightness and contrast. This image editor is also bundled with auto-recovery feature that can backup any unsaved images, Background Save option, Blur Gallery, Crop tool, video creation, and a whole lot more. With all these new improved features and a modern user-friendly interface, editing digital photos can never be so fun and easy without Photoshop CS6.

Adobe Photoshop CS6 for Mac

Adobe Photoshop CS6 for Mac

Adobe Photoshop CS6 for Mac is the version of “Creative Suite” image managing software designed exclusively for Mac computers, particularly Mac OS X v10.6 to 10.7 in 64-bit. This image editing program is bundled with a new set of features and tools, such as the Mercury Graphics Engine developed by the same company for fast and high quality image enhancing performance, Content-Aware features, intuitive re-imagined tools for movie designing, workflows , Blur Gallery, Crop tool and a whole lot more. The Adobe Mercury Graphics Engine functions in a way that it makes editing task easy and fast to complete. This also allows the sharing and migration of images with auto-recovery and Background Save options. The new Content-Aware tools are made for easy and controllable way of retouching or enhancing images that result in a more satisfied output. It basically lets any user to auto-correct images, crop them and correct wide angle lens curvatures.

ACD Systems Canvas 14

ACD Systems Canvas 14

ACD Systems International Inc. is the developer of ACD Systems Canvas 14, which is a technical graphics solution software, that enables users to analyze data, enhance graphics and share all information with ease and rapidity. This program is designed with full-featured tools that assist users in making technical graphics and illustrations with accuracy. It consists of editing tools that vary from image editing to object illustration tools. Any results created by this program make good presentations for projects, proposals and other purposes for any line of business related to graphics and engineering. More on the features, users can work with raster images and vector graphics using the same file with the option edit by resizing and scaling objects, drawing shapes, as well as inserting stroke and fill inks or widths. There is also a tool for adding texts or labels and format dimensions, plus creating charts. With this program, users can share finished projects through presentations or publications.

ACD Systems ACDSee 15

ACD Systems ACDSee 15

ACD Systems ACDSee 15 is a photography software that features an image organizer, viewer, and RAW/ image editor program for Microsoft Windows and Mac OS X 10.6 (Windows XP with Service Pack 2, Vista, 7 & 8; Mac OS X 10.5, 10.6 , 10.7 and Mountain Lion). It was developed by ACD Systems International, Inc. and originally distributed as a 16-bit application that was later upgraded with a 32-bit version. This minimum hardware requirement for this application is an Intel Pentium III/ AMD Athlon processor or equivalent with 512 MB RAM (with 310 MB free hard drive space), a high color display adapter at 1024 x 768 resolution, and a CD/ DVD burner. ACDSee manages and supports video and audio files in formats that include GIF, BMP, JPG, PNG, MP3, PSD, WAV, MPEG, and TIFF. Users can view, edit, add effects, and organize photo and video collections that can be shared online. Photos can be organized as these are imported from the camera or other storage device. It also features Map view and geo-tagging support that enable users to view the location of images from GPS-enabled cameras. Features like fast browsing, scanning, editing, and backup options facilitate sorting of photos by date and event, and storage of backup copies to CD, DVD, and Blu-Ray.

PNG (Portable Network Graphics) - graphic format raster type containing an 8-bit color palette. The Deflate compression algorithm developed for PNG files reduces the size of the saved image without losing the quality of the final image.

In this article you will also learn how to open a PNG file.

Characteristic

PNG is the second most popular Internet format after JPG.

Among other advantages it is worth noting:

• interlaced layout;
• built-in software correction of color palette and gamma.

The latter allows you to sew everything into the image required parameters display so that it looks on all screens as the author intended.

The format has 2 versions:

• PNG-8 (index color scheme is similar to that of GIF);
• PNG-24 (full and full color palette simulating JPEG).

History of origin

In 1995, during the era of the development of the free Internet, the question of the proprietary nature of the complex GIF format suddenly arose. An equally reliable but free and free format was needed for exchanging graphic data on the World Wide Web. At this time, the international W3C consortium presented the PNG 1.0 specifications, approved already in 1996.

The format was created as an alternative to GIF. The latter was “closed” until 2004, that is, it had a number of restrictions for free use (required the owner’s copyright when saving, patent licenses when posting). PNG was deprived of such shortcomings, while implementing support for color depth up to 48 bits and an 8-bit alpha channel for image transmission.

The developers managed to create a smooth transparency of colors that is impossible in GIF. In the latter, the palette is limited to an 8-bit channel (256 colors) and only supports full transparency.

How to open PNG files

Today, the graphic format can be easily displayed in an Internet browser and standard means to view graphics. To put it in more detail, the picture is as follows: each OS has its own tools for working with the format. Let's take a closer look at how to open the PNG format.

Online

To view files on the Internet, use the following software:

Windows 7-10

Windows operating systems open the PNG format in the following way:

• photo viewer;
• MS Paint;
• web browser (view only).

Android

The mobile OS has the following tools:

iOS

Mobile cat for Apple works with PNG files using such software.

Computer graphics have now filled everything around us, we even look at photographs more often on a monitor, phone or TV screen than on paper. But what’s most interesting is that the ways these images are stored are very different. There are dozens of image storage formats, each with its own advantages and disadvantages, but the most effective and popular of them remain those that provide best quality And besides, the file turns out to be small. One such format is the PNG format. What is this format and where did it come from?

Briefly about the very reason for the appearance of this image storage format...

On January 4, 1995, the idea of ​​creating free format instead of a paid GIF, and already in December of the same year new format PNG was already ready and proposed for consideration. The GIF format at that time made it possible to obtain very small files that were convenient to use on websites. But the formerly free GIF suddenly became paid - the owner of the patent for it, Unisys Corporation, intended to charge money for each image that uses this format. This was the reason for the development of a free format called PNG, an abbreviation for the English expression “portable network graphics”. As the name implies, it is intended for use on the network, due to the small files, which allows pages with graphics to load faster.

What are the advantages and disadvantages of the PNG format compared to others, especially its main competitor, the GIF format? There are a lot of differences, but first things first...

The PNG format uses a compression algorithm called Deflate, which itself is open source, meaning it's completely free. This algorithm works on the principle of a conventional archiver, effectively compressing information about color scheme each pixel, and it is this that allows you to get a fairly small file. In addition, in this format you can save full-color images, that is, those that use up to 48 bits per pixel - and this is a very large color gamut, even more than the human eye can perceive. The GIF format allows you to use only 256 colors and shades - enough for the simplest pictures, but very little for photographic quality.

PNG, GIF and TIFF formats use the so-called alpha channel. This means that you can make some parts of the picture transparent. At the same time, in the GIF format this is done very simply - just one of the colors to choose from is assigned transparent and when viewing the image it is simply not visible - this is how you can make a transparent background. TIFF format more thought out in this regard, but it is very rarely used - the file size is too large. But in the PNG format, the alpha channel is made wisely - not only is there transparency, but it also has 256 gradations of brightness. That is, you can easily make the transition from a completely transparent background to a full-color image, and get beautiful effects. It looks especially beautiful on websites. If transparency is not needed, you can simply not use it when saving the image and get an even smaller file.

Unfortunately, the PNG format has one drawback, not a very significant one - it does not allow saving a sequence of images, the so-called animation. GIF allows you to do this. This happened because at the time of the creation of the new format, animation was practically not used anywhere, and in 1995 there was no particular need for colorful websites, so animation was excluded from the project as unnecessary. Today, the niche of animation has been occupied by Flash technology, which is not a competitor to any conventional graphic format.

If the PNG format is so good, then why hasn't it become super popular? The answer is simple - it was poorly supported by the developers of other programs. Particularly influential was the fact that the majority of Internet users used Internet browser Explorer, but it didn’t “understand” images in PNG format, although the developers of other browsers immediately built such support into them. The situation improved only when Internet Explorer 7 appeared, but the time for “promotion” has long passed.

Today, the PNG format is one of the three most popular and recommended formats in web technologies, along with GIF and JPG formats. And, if you don’t consider the lack of animation as a disadvantage, then it wins in all respects compared to others. A high-quality image without loss of quality, a small file, smooth transitions to a transparent background, and without violating anyone’s copyrights - what else does a website developer need to be happy?

Announcement

PNG Raster image file format

PNG files (commonly called "pings") are files in a format that contains raster images. The PNG image format was originally created as a transition from the GIF format, as they both have the ability to display transparent backgrounds. Other similarities between these formats are the use of indexed colors and lossless compression. However, PNG files have different sets of copyright restrictions. Moreover, unlike GIF images, files with the PNG extension do not support animation. On the website Online-onvert.com you can easily and completely free of charge.

Technical information about PNG files

PNG images are the best solution(compared with GIF files) due to the fact that the former use, among other things, an 8-bit transparency channel, and also support 24-bit RGB colors, RGB and grayscale images. Files with the PNG extension were designed to make them easier to transfer over the Internet. As a non-professional image format, PNG does not support other color spaces.

Additional information about the PNG format

File extension	.png
File category
Example file	(16.5 MiB) (3.8 MiB) (325.40 KiB)
Related programs	Microsoft Windows Photos Microsoft Paint Adobe Photoshop CC