PNG Image Extension
PNG (an acronym for Portable Network Graphics, and also referred to as PING) is a format that uses raster graphics and lossless compression which prevents images from losing data.
It appeared later than JPEG or GIF, and has some advantages in comparison to them. For example, this format can provide a transparent background for a picture; the quality decrease of the picture is less in relation to the compression and the size of the file is relatively small as well.
However, it’s not suitable for animation or for printing.
PNG Technical Details
This extension also supports grayscale, truecolor and palette-based types of graphics. It handles up to 48 bits per pixel and up to 16 bits per pixel for truecolor and for grayscale respectively. It can contain 16 million colors and 256 layers of transparency (from completely transparent to completely opaque). PING also contains Alpha channels, so pallets support 24-bit GBR and 32-bit GBRA.