What does png mean? Programs for viewing and editing images
A PNG file can be opened with special programs. To open this format, download one of the proposed programs.
. PNG file extension.
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.
What's in PNG files
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 , PNG files do not support animation.
The PNG format has both grayscale and full-color photographs, and transparent layers are supported. PNG compression 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 file Yes, you can use any Internet browser or graphic editor. Both Windows and Mac OS platforms have built-in mechanisms for viewing such images. Png Program - Viewer Windows photos the default is often used to open PNG files because it system program Windows. 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 already on your computer using the combination Ctrl keys+ O. Most of these programs also support drag-and-drop, so you can simply drag the PNG file into the browser to open it.
PNG conversion
Image files can be converted in various ways eg 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 file, but without restrictions on copying. Typically used to store web image graphics.
The PNG format (pronounced .png) was created in response to the format's limitations, primarily to increase color support and provide a patent-free image format. In addition to this, while the files
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 |
|
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 in this case this is an Up filter that 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. This 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 and come to the rescue, which large number aisles are being picked up different ways filtering and data compression strategies, 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 best way data encoding.
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.
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8167 bytes |
6132 bytes |
The advantages of greyscale over truecolor are obvious: for example, white in the first case it is written (in decimal system notation) with the number 255, and in the second - 16777215.
Now, armed with knowledge about storing data in PNG format, we can use them in preparing images for the web. More on this in the following articles.
The PNG raster graphic format appeared as a kind of maidan of free developers against the technological oligarchy, acquisitiveness and thirst for profit that were stifling the development of the Internet.
In the mid-nineties of the last century, the First Internet Revolution was in full swing. Consortium worldwide network W3C, as a result of a bloodless coup, removed the legally elected (by bribing the electorate) Temporary Representation in the person of Microsoft and Netscape. The latter were unable to agree on standards and brought the young digital civilization to the brink of a browser war.
Overdue urgent need introduction of universal unification of Internet technologies. However, the GIF graphics format that existed at that time had a small but significant drawback– he had a commercial license, including data compression technology.
As usual, no one wanted to pay, therefore, in order to avoid chaos on the World Wide Web, when the sites of one developer cannot be viewed on the browsers of another, a group of volunteer programmers created the PNG specification, which turned out to be no worse than GIF, and in some respects had significant advantages.
Technical features of the PNG format
In general, if you look closely, PNG differs from GIF about the same way MS Office differs from LibreOffice. At the core raster graphics compressed, indexed color palette. However, the PNG developers took into account the errors of GIF and managed to eliminate new technology from the oppressive problems of the past.
- The PNG data compression scheme ensured that the original image was completely lossless, regardless of the compression level.
- Higher level of data compression.
- It was allowed to use an unlimited number of colors in the image. This made it possible to ensure the quality and realism of the picture almost at the level of the JPEG photographic format.
- Support for multi-level transparency of layers.
- The PNG format allows you to save all intermediate stages of image editing and restore any step without loss of quality.
There were attempts to create versions of this format with the possibility of animation, but they were no longer in demand - at the beginning of the 21st century, the license expired and the GIF graphics format became free for use for any purpose.
Scope of application PNG
Portable Network Graphics roughly translates to "portable network graphics"Even in the name of the project there is a noticeable imitation of GIF - “graphic format for exchange over networks.”
To disavow the dark past, the creators of PNG spread the recursive acronym “Ping is Not a GIF” on the Internet.
Ping is the British pronunciation of PNG, in American English it sounds more like P-n-ji, for a Russian-speaking observer - peenge.
In fact, the revolutionary graphics packaging format turned out to be very good and today is the most popular for preparing images for publication on websites, blogs and social networks thanks to its outstanding qualities.
- Cross-platform – read equally well by all types of modern browsers and graphic editors.
- Has low weight high quality images.
- Easily compressed in a wide range without loss of quality.
However, when posting photos on sites for viewing on screens computer monitors, especially on small displays mobile devices, users will not notice any difference between a PNG and a JPEG photo. More precisely, to notice the difference you need to either look closely or be a professional photographer.
For websites, the light weight of images is more important so as not to slow down the loading of web pages.
If we take into account the statistics that, on average, visitors spend only a few seconds on websites, and the content is not studied in detail, but is superficially scanned with a quick glance, then the quality PNG images turns out to be optimal.
Advantages of PNG over JPEG
In the process of repeated compression and editing of the image in JPEG files become distorted, color halos appear, and pixel blocks may fall out.
If you need to publish a very clear diagram on a website page, with legible small details, infographics - here PNG shows significantly better results than JPEG, which is optimal for packaging images in which the main requirement is realism - photographs of natural landscapes, animals, people.
Possibility of creating transparent layers makes the PNG format indispensable for developing logos, icons, symbols, and buttons.
PNG has a function for storing metadata - date, time, place where the image was created, information about the author, copyright holders, etc. This is useful to remember when you are going to publish a picture borrowed from the Internet. To prevent Google from identifying a duplicate, you need to remove metadata from the file (using a graphic editor).
Free online image converter to PNG
On this site you can easily convert almost any image into PNG format, and you can set the color depth from 1-bit to 64-bit, as well as set the compression level. 
Please note that in order to maintain transparency in the resulting image, you need to use depth with RGBA colors. In this case, the letter A means alpha channel, i.e. transparent.
PNG optimization
Not all programs do PNG with minimum size file. Therefore, before publishing a picture on the site, it is recommended to optimize it. For these purposes, you can use various utilities, or use our online optimization service. Just select an image and click "Optimize".
Instructions
Much depends on what graphic editor you are working in. The simplest programs, such as the standard Paint editor, do not support transparency at all. More functional programs Paint.net, CorelDraw, Adobe Photoshop(and similar ones) allow you to adjust the transparency of images and support working with layers.
To adjust the transparency (partial transparency) of an image or any part of it, create new layers and use your editor's tools to adjust how the layers appear. Depending on your editor, you may have to merge all layers before saving.
To save the image as you see it in the editor, select top line menu item “File”. From the drop-down menu, select the “Save as” command. In the dialog box that opens, specify the directory to save the file; in the “File name” field, enter the name under which you want to save the file. In the “File type” (Format) field, select the value PNG(*.PNG) from the drop-down list and click on the “Save” button.
If merging layers leads to loss of transparency, either save the image without merging the layers, or set your editor to a tool that allows you to export layers in .png format without (for example, in Adobe Photoshop standard tools This cannot be achieved, since there is no .png extension in the list of formats).
Download the corresponding script from the Internet. Set a transparent layer as the background, and place the main image on another layer. Select the “File” item in the top menu bar, the “Scripts” item in the expanded menu and the “Export Layers to File” command.
In the dialog box that opens, select the directory to save the layers, check the box next to Fast Mode (Don't remove hidden layers), select the .png format in the "File type" field and click the "Run" button. This action will result in you having two files saved: one “empty”, the other will contain an image with your transparency settings.
Sources:
- PNG and Photoshop
The images on the computer are in the form digital files, the format of which depends on the type and purpose of the graphics. Conventionally, all these formats are divided into two large groups- for displaying pictures on the monitor screen and for printing.
png - graphic format for the Internet
Of all those used today graphic formats For web images, three are most often used - gif, jpeg and the young, but very promising png format. Developed in 1995 as an alternative to GIF, which did not satisfy all user requests, it is intended for images that are planned to be used on the Internet. Unlike gif, png format supports 24-bit images and background transparency without jagged edges.The main advantages of the png format are support for any colors, work with transparent pixels, efficient algorithm compression without loss of image quality. Unlike gif, which only supports full transparency, png also preserves semi-transparent pixels (1-99%) through its 256-gray alpha channel. Built-in gamma correction allows colors to be displayed without distortion on any computer, regardless of platform. This format has the ability to load with interlaced scanning, and double - horizontally and vertically.
png format supported color models RGB, Grayscale, Indexed Color and Bitmap without alpha channels. It is not intended for use with professional graphics and does not provide CMYK color support.
How to view a file with a png extension
The easiest way to open such a file is to double-click on it with the left mouse button. Even if you don't have any installed on your computer additional programs, “Windows Photo Viewer” will launch and the picture will be opened. In addition, this format opens graphical images without problems. paint editor(in which you can also edit the image, as well as create a new one) and Internet browser Explorer included in the standard software package.For more comfortable work with images it is better to install on your computer special programs, intended for their sorting, viewing and processing. The png format is graphic file, so any of these programs can easily work with it. There are quite a few free applications, the functionality of which is quite sufficient to solve most emerging problems.
If the system cannot open a file with a png extension, you need to reinstall standard applications and check windows registry for errors.
Programs for viewing and editing images
Picasa is a program designed for viewing and editing images. It has built-in filters that will help you quickly and efficiently process the image. In addition, in Picasa you can use photos by selecting transitions and adding sound.FastStone Image Viewer - convenient application For home use. Includes all basic image processing functions. The main advantage of this program is viewing the image open in full screen with an increase in individual details. This will allow you to look at any area in detail. A slideshow made with FastStone will have exe extension, so it will run easily even on the oldest computer.
XnView is very functional program with a clear interface. Photos can not only be viewed, but also edited. Frequently used operations such as photo rotation, color alignment, or red-eye removal are available right in the viewing window. In addition, in this program you can create a blur effect or improve clarity. XnView has many useful options. For example, search, group processing, and creating slideshows.
Ashampoo Photo Commander FREE is a high-quality utility for viewing and processing graphics. It has built-in effects such as sepia, shadow and sharpening, allows you to crop and rotate the image. In addition to the basic functions, it has the ability to take pictures of your desktop, burn photos to a CD or DVD, convert images and send them via email address. In addition, you can create collages in it.
In addition to graphic editors and image viewers, files with the png extension can be opened in any modern browser, as well as in Microsoft Office Word.
All programs reviewed are completely free. There are many other similar applications. Among them we can note, for example, Honeyview, which allows you to view photos directly from zip archive, 7z or rar without unpacking them. The Irfan View image viewer is also worth a look. Its functionality can be significantly increased with the help of plugins, the choice of which will depend on the tasks facing a particular user.
One of the main tasks facing designers of new sites is fast loading browser pages. And since not all users like minimalistic design, we have to find a compromise between beautiful design with graceful graphic elements and the speed of the web resource. Previously, in order to reduce the weight of images, website developers used either GIF or JPG. Nowadays, layout designers are increasingly using images in PNG format. Let's try to figure out together why this happens.
Why was the PNG format invented?
The abbreviation that is the name of this type of graphics is formed from the first letters of the following English words: portable network graphics, which can be translated as “movable graphics for use on the network.” The PNG format was specifically invented to eliminate the disadvantages of compression using more simple algorithm GIF, which is slowly starting to become outdated. In addition, it can to some extent be used to replace the much bulkier TIFF, which is used mainly for editing.
What is the PNG format?
Today, two versions of this algorithm are widely used. In the first case, 8-bit is used, and in the second, 24-bit. Photos in PNG-8 format, compared to the GIF version, are slightly better and lack the ability to create animation. Although it can contain a maximum of 256 colors, this algorithm Widely used to create graphic text, logos, illustrations with sharp edges and pictures with gradient transparency. In cases where this is clearly not enough, developers use the 24-bit PNG format, which has a lot of additional benefits, such as:
- Improved negating any loss of quality.
- The ability to use alpha transparency provides 256 different levels transparency.
- The presence of gamma correction, which allows you to automatically adjust the brightness of the image when playing back in different programs.
- Possibility of using about 16.7 million color shades.
All this together contributes to the use of PNG24 for compressing any images containing transparent areas, drawings with a large number colors and clear image boundaries.
Development trend
Despite the fact that the spread of the PNG format is still hampered by older browsers, as well as insufficient and incomplete support for the capabilities of this algorithm in new versions, PNG is very promising for web graphics. Compared to GIF, it has three main advantages: alpha channels, gamma correction, and 2D interlacing (a method of progressively displaying an image). And compared to JPEG, it has no quality loss. Note that the PNG format was invented on January 4, 1995. 18 years have passed since then, and it has become the leader in use on websites, pushing GIF into second place.
Most user applications (for example MS Paint) today have adopted it as the standard for saving files “by default”. Probably, if not for the animation and quirks of the old Internet versions Explorer, GIF would have given way to its competitor even earlier.