Over the past year, animated images have become an integral part of social networks and entertainment resources. In this regard, users of VKontakte and other social media were interested in the question of what a gif is.
Format concept
GIF can be decrypted as "a format intended for the exchange of graphic images." It was developed by CompuServe in 1987 in order to send raster images over the network.
Pictures with the .GIF extension can be stored without sacrificing quality and count up to 256 of the most common colors. It is possible to support more shades in animations if there is a separate palette for each frame and there is zero delay between shows. The format implies working with a standard color palette. The image is saved line by line. Thanks to LZW compression, files with a large number of homogeneous sections are easily compressed. The image does not lose clarity.
Enhanced GIFs
What does a gif mean for a modern user if there is no animation in it? This is not at all what he wanted. Therefore, shortly after creation, the format was improved: since 1989, GIF-files can be dynamic and contain transparent areas. An animated GIF is an image that contains several frames, as well as information about the frequency and order of their output to the screen. As a rule, the process is looped, and after the end of the show, the gif starts again.
Among the colors of the palette can be declared transparent. In this case, modern browsers will display the background through unpainted areas. Partial transparency supported in PNG is not typical for GIFs: a pixel can be either filled or transparent.
Where is the GIF format used?
Having found out what a gif is, we can conclude: this type of image is very convenient to use where the file should have a minimum size. The Internet is such an area: in pursuit of page loading speed, developers try to use as few “heavy" pictures as possible, preferring lightweight gifs.
GIF format is common in web design. It is perfect for transferring small pictures, including those containing text. Beautifully designed buttons with a variety of inscriptions are nothing more than gifs. However, GIFs are not suitable for saving photos. JPEG (JPG) is ideal for this purpose: this format is not limited in the number of colors displayed.
Animated gifs are often used in website design. Due to the ability to leave pixels transparent, GIF images fit perfectly into a series of other images.
Specifications
What is a gif? First of all, it is a reduced in weight image. The format involves LZW compression, which allows you to combine repeating pixels. Therefore, the more homogeneous areas, the stronger the image will be reduced. The algorithm allows you to reduce the size of eight-bit images with a palette without sacrificing quality: the packed data can be completely restored. As for photographs, the limitation of 256 colors will be irreversible.
The LZW algorithm searches for identical sections of a file called phrases, assigns markers to them, and puts them in a table. For example, in the picture there are 70 sets of pixels painted in orange, yellow and pink. Each of them will be assigned the same value - for example, 8. The data will be saved 70 times as a record with an eight. The less noise in the picture, the better compression will be.
Another feature of the format is the interlaced way of storing information. Lines are divided into groups, their order inside the file is changed. While the image is loading, it gradually appears. Thus, until the gif has fully loaded, it can be seen, but only with a lower resolution.
First, 1, 5, 9 and further lines are written with an interval of “4”, in the same order they appear at boot time. When 25% is downloaded, you can see a blurry picture. Then 3, 7, 11 and further lines appear, the image becomes 2 times sharper. Then the remaining rows are loaded (2, 6, 10 ... and 4, 8, 12 ...) and the picture becomes final. This recording method slightly increases the size of the gif, but the ability to see it before the download is complete justifies this small drawback.
What is the VKontakte GIF?
Animated pictures uploaded by VK users are those same moving GIF images. Those who already know what a gif is, it will be interesting to learn about how to post it on a social network.
To insert an animation from another site, you need to right-click on it and find the item in the menu that allows you to copy the address (URL). Then you need to go to the VKontakte website and paste the address in the place where the gif should appear (for example, in the field where you write the text of the post on the wall). The system will automatically download the picture, after which the link can be removed. Press Enter to post the gif.
To download a gif from a computer, you need to place it in the “Documents” section (the section itself opens in the settings). Click "add document", select the access level. To place a gif in a message or post, you must click the "Attach" button and find the desired file.
Animated pictures seen with friends, you can save yourself. To do this, expand the image with the “+” button, right-click on it and select the desired item in the menu.
What are gifs in VK? This is a great way to decorate your profile, express emotions, entertain yourself and friends. Add animations to chat or wall from your own computer or Internet sites: now you know how to do it!