SGI (image file format)
From Just Solve the File Format Problem
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* [[Netpbm]]: pnmtosgi, sgitopnm | * [[Netpbm]]: pnmtosgi, sgitopnm | ||
* [[ImageMagick]] (format named "SGI") | * [[ImageMagick]] (format named "SGI") | ||
| + | * [[Tom's Viewer]] | ||
* [http://svn.osgeo.org/grass/grass/branches/releasebranch_5_5/src.contrib/CERL/SGI/libimage/ libimage] | * [http://svn.osgeo.org/grass/grass/branches/releasebranch_5_5/src.contrib/CERL/SGI/libimage/ libimage] | ||
Revision as of 21:52, 27 April 2019
SGI (also known as IRIS, and sometimes called RGB or Irix RGB) is a raster image file format. The image may be uncompressed, or use RLE compression.
SGI probably stands for Silicon Graphics Image.
Contents |
Image types
SGI supports the following image types:
- Grayscale, 8 or 16 bits/sample
- RGB, 8 or 16 bits/sample
- RGBA, 8 or 16 bits/sample
- RGB 3-3-2, 8 bits/pixel (obsolete)
- Colormapped (but no palette is stored in the file) (obsolete)
- Colormap (file contains only a palette; no image) (obsolete)
Format
SGI files start with a 512-byte fixed header, most of which is unused. If the image is uncompressed, the pixel data follows. Compressed images have a scanline table, followed by the compressed pixel data.
The pixel data is stored from bottom-up, instead of top-down as in most image formats.
Identification
SGI files begin with bytes 01 DA.
Specifications
Software
- Konvertor
- Netpbm: pnmtosgi, sgitopnm
- ImageMagick (format named "SGI")
- Tom's Viewer
- libimage
