SGI (image file format)
From Just Solve the File Format Problem
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SGI probably stands for '''Silicon Graphics Image'''. | SGI probably stands for '''Silicon Graphics Image'''. | ||
| + | |||
| + | == 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 == | == Identification == | ||
Revision as of 18:36, 20 July 2013
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
- Netpbm: pnmtosgi, sgitopnm
- ImageMagick (format named "SGI")
- libimage
