Also known as: TGA
--------I-TARGA----------------------------- The Targa-File format is an image file format used by a wide variety of both scanners and imaging software, and exists in many incarnations. The information has been taken from Appendix C of the Truevision Technical Guide.Requests for further information could be directed to: AT&T Electronic Photography and Imaging Center 2002 Wellesley Ave. Indianapolis, IN 42619 The lack of completeness is due to the fact that the Targa recognizes over half a dozen image file formats, some of which are more widely used than others. OFFSET Count TYPE Description 0000h 1 byte Length of image identification field (below) 0001h 1 byte Color map type : 0 - no color map 1 - 256 entry palette 0002h 1 byte Image type : 0 - no image data included 1 - Uncompressed, color-mapped image 2 - Uncompressed, RGB image 3 - Uncompressed, black and white image 9 - RLE encoded color-mapped image 10 - RLE encoded RGB image 11 - Compressed, black and white image 32 - Compressed color-mapped data, using Huffman, Delta, and runlength encoding. 33 - Compressed color-mapped data, using Huffman, Delta, and RLE. 4-pass quadtree- type process. 0003h 1 word Index of first color map entry 0005h 1 word Count of color map entries 0007h 1 byte Number of bits per color map entry 0008h 1 word X coordinate of the lower left corner of the image. 000Ah 1 word Y coordinate of the lower left corner of the image. 000Ch 1 word Width of the image in pixels 000Eh 1 word Height of the image in pixels 0010h 1 byte Bytes per pixel 0011h 1 byte Flags (bitmapped): 0-3 : Number of attribute bits 4 : reserved 5 : Screen origin in upper left corner 6-7 : Data storage interleave 00 - no interleave 01 - even/odd interleave 10 - four way interleave 11 - reserved The byte should be set to 0. Don't know why. 0012h ? char Image identification string, usually not there, when the length (see up) is 0. ????h ? byte Color map data Depending on the number of bits per color map entry, the entries here have a different size. 4 bytes : 1 byte for blue 1 byte for green 1 byte for red 1 byte for attribute 3 bytes : 1 byte for blue 1 byte for green 1 byte for red 2 bytes : Bitmapped as a word in Intel byte order as follows : ARRRRRGG GGGBBBBB ????h ? byte Image data For images of type 9 (using RLE), the image data is divided into packets, the first byte being the indicator for repetition or copy. If bit 7 of the first byte is set, then repeat (first byte and 07Fh+1) times the next byte, otherwise copy first byte+1 pixels from data stream. RLE packets may cross scan lines ! EXTENSION:TGA OCCURENCES:PC SEE ALSO:
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