PNG pronounced ping is a format for storing bitmapped (raster) images on computers. It was created originally to replace the GIF file format when it was announced that the companies who created the GIF format wanted royalties. PNG uses indexed colors and lossless compression (like a .GIF file), but without those copyright limitations; it cannot be animated like a GIF image.
PNG images are in many ways better than .GIF as they also include an 8-bit transparency channel, which allows the colors in the image to fade from opaque to transparent; GIF images only support fully opaque or fully transparent pixels. PNG supports palettes of 24-bit RGB colors, RGB images or greyscale or RGB images. PNG was intended to be able to transfer images on the Internet, not professional graphics, and so does not support other colour spaces (such as CMYK).
Apple Preview Corel Paint Shop Pro GIMP - The GNU Image Manipulation Program (LINUX) Microsoft Windows Photo Gallery Viewer Safari
Development of the TGA file format began in the mid eighties. A TGA file is most commonly associated with a TARGA image file (Truevision Advanced Raster Graphics Adapter). TGA files are bitmapped images, they were originally developed for use with Truevision's (now Pinnacle Systems) high-end graphics cards which were designed for video editing. TGA files are often seen in the video and animation industry, as well as by computer game manufacturers who use the TGA format to store texture files.
TGA files can store images with a range of bits, these include 8-bit, 16-bit, 24-bit or 32-bit which is 24-bit colour with transparency. They use a palette to define all available colours in an image. TGA images have typically large file sizes as every pixel is represented by a certain number of bits (dependant on the colour depth). However, they can be compressed using simple lossless run-length encoding, which can result in greatly reduced file sizes.