File Extension TGA
File extension TGA is most commonly associated with a TARGA image file, which is an abbreviation for Truevision Advanced Raster Graphics Adapter. TGA files are bitmapped images, and were originally developed for use with Truevision's (now Pinnacle Systems) high-end graphics cards which were designed for video editing.
Development of the TGA file format began in 1984, though it was not until 1989 that significant extensions were added to the format to make it more suitable for use by graphics professionals. These improvements included a 32-bit colour depth, which was essentially truecolour (24-bits per pixel) with an additional 8-bit alpha channel adding transparency. The ability to attach information to TGA files, such as creation date, author and a postage stamp, otherwise known as a thumbnail or scaled-down preview - was also added. The major rival to the TGA format was the Tagged Image File Format, or File extension TIFF. Though technically superior, support and portability between different platforms was not as widespread which is why the TGA file format still remains popular today.
TGA files can store images with 8-bit (256 colours), 16-bit (65,536 colours), 24-bit (16,777,216 colours) or 32-bit (24-bit colour with transparency) colour depth, or 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.
TGA files are used extensively in the video and animation industry, as well as by computer game manufacturers who often use the TGA format to store texture files.
Support for TGA files is widespread, and they can be opened and manipulated by the majority of major image editing applications including Adobe Photoshop, Corel Paint Shop Pro, Painter and GIMP (GNU Image Manipulation Program).