Information about PNG
|Raster image file
|Portable Network Graphics
|PNG development Group(Donated to World wide web Consortium/ W3C)
|These files are commonly termed as ‘ping' and they store the raster files using lossless compression. It came into existence in order to replace the GIF file format as they both have the ability to show transparent backgrounds. Furthermore, it was an enhanced and improved version of Graphics Interchange format. It supports different types of photos. The first one is palette-based photographs that can either have palettes of 24-bit RGB or 32-bit RGBA colours. Second is grayscale images which may or may not have an alpha channel for transparency. Lastly, there is a full-colour non-palette which is based on RGB/RGBA pictures. There is one limitation of this type. It does not support animation like GIF. Besides this, it is non-patented which means there are no copyright limitations.
|The expanded features like 8- bit channel for transparency and 24- bit RGB support make PNG more popular. The files stores in this format allow the fading of colours from opaque to transparent which is not present in the preceding format. CMYK does not offer support to this extension as it was developed for transferring of files over the internet, not for professional-quality print graphics. It stores information like textual comments, integrity checks and encoded basic pixels in its extensible structure of chunks. It always starts with an 8-byte signature followed by a series of chunks. A chunk furthermore comprises of four parts- length (4 bytes), chunk type (4 bytes), chunk data (length bytes) and CRC- Cyclic redundancy checksum or code (4 bytes).