SGI (image file format)
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== Sample files == | == Sample files == | ||
* [http://ftp.funet.fi/index/graphics/packages/volvis/RGB.tar.Z RGB.tar.Z] | * [http://ftp.funet.fi/index/graphics/packages/volvis/RGB.tar.Z RGB.tar.Z] | ||
| + | * https://telparia.com/fileFormatSamples/image/sgi/ | ||
== External links == | == External links == | ||
Revision as of 16:48, 1 August 2020
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
