Drop SGI image files here (.rgb, .sgi, .bw, .rgba)
Or choose files from your device. Everything is converted in your browser; nothing is uploaded.
How to convert an SGI image to PNG
- Drop one or more SGI files (
.rgb,.sgi,.bw,.rgba) into the box above, or choose them from your device..gzcopies are unzipped automatically. - Check the preview. Compression, bit depth, row order and transparency are all detected automatically.
- Pick a PNG size. 1× keeps the original pixel dimensions; larger sizes enlarge each pixel into a crisp square.
- Download each PNG on its own, or download every converted file at once as a ZIP.
What is an SGI image file?
The SGI image format, also called IRIS RGB, was created by Silicon Graphics for its IRIX workstations, the machines behind much of the 3D graphics, film effects and scientific visualization work of the late 1980s and 1990s. Files usually end in .rgb for color, .rgba for color with transparency, and .bw for grayscale, with .sgi as a general extension.
You'll still run into SGI files in old 3D model texture folders, early OpenGL and OpenFlight datasets, legacy VFX archives, and software like Blender and Nuke that can still write them. Browsers and most image viewers can't open them, so PNG is the practical way to view, share or reuse them.
Supported SGI variants
| Channels | Typical extension | Converts to |
|---|---|---|
| 1 | .bw | Grayscale PNG |
| 2 | .bw, .sgi | Grayscale PNG with transparency |
| 3 | .rgb | Full color PNG |
| 4 | .rgba | Full color PNG with transparency |
Both uncompressed (verbatim) and run-length encoded (RLE) files work, at 8 or 16 bits per channel. 16-bit images are reduced to 8-bit PNG. When a 16-bit file only uses part of the range, such as 12-bit scanner or medical data, the converter uses the header's maximum value so the image isn't left almost black.
SGI to PNG converter FAQ
Are my files uploaded anywhere?
No. The files are read and converted by JavaScript running in your own browser. Nothing is sent to a server.
Why are SGI images stored upside down?
SGI files store rows from the bottom of the image to the top, matching how IRIX graphics hardware drew the screen. The converter flips them automatically, so the PNG comes out the right way up.
Does it keep transparency?
Yes. Files with 2 channels (gray plus alpha) or 4 channels (RGBA) become PNGs with transparency. Tick Ignore transparency if you want a solid image instead, for example when the alpha channel is empty by mistake.
My 16-bit SGI file looks too dark in other converters. Will it here?
Many 16-bit SGI files only use 12 or 10 bits of the range. Converters that assume the full 16-bit range turn those images nearly black. This tool reads the maximum value from the file header and scales to that when the image data fits it. The file card shows when this happens.
A file failed with a damaged-data message. What can I do?
The converter already copes with the common problems: row tables written in either offset style, missing length values and rows that end early. If a file still fails, the card explains what's wrong. Rows it couldn't recover are left transparent rather than stopping the whole conversion.
Can I convert many files at once?
Yes. Drop or select as many files as you like, then use Download all as ZIP to save every PNG in one archive.
More legacy image converters