JPG to SGI Converter
Convert JPG to SGI in your browser. JPG files usually come from cameras, phones, scanners and almost every app that saves photos; SGI is the better fit for legacy SGI and 3D pipelines. You get an 8-bit run-length encoded SGI image, RGB, or RGBA when there is transparency. Nothing is uploaded.
- Processed locally
- No upload, no wait
- No sign-up
- No watermark
Drop images here
or choose files · paste with Ctrl/⌘ V
JPG expected · other image formats also work
How to use JPG to SGI
- 1
Add your JPG files: drop them here, choose them, or paste from the clipboard.
- 2
There is nothing to tune: the SGI is written losslessly. Resizing and rotating are under More options if you need them.
- 3
Click Convert. Each file is decoded and encoded in a background thread on this device.
- 4
Download the .sgi files one at a time or together as a ZIP.
Why use Aback Images for jpg to sgi
Where the SGI goes next
SGI opens in Blender, GIMP, ImageMagick, Nuke, XnView and IrfanView.
SGI next to JPG
The SGI keeps the decoded pixels without lossy compression, so expect it to be larger than the JPG.
No new artefacts
JPG is already lossy, since it stores lossy DCT coding in 8×8 pixel blocks, with colour usually stored at half resolution; the SGI keeps the decoded pixels losslessly, so this step adds no compression damage of its own.
Processed on your device
Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.
JPG vs SGI
What changes from JPG to SGI
Encoding: the JPG uses lossy DCT coding in 8×8 pixel blocks, with colour usually stored at half resolution; SGI uses uncompressed (verbatim) or per-row run-length encoding, and the download is an 8-bit run-length encoded SGI image, RGB, or RGBA when there is transparency.
Bit depth: 8 bits per channel in the JPG; SGI allows 8 or 16 bits per channel, and the SGI written here has 8 bits per channel.
Colour: YCbCr shown as RGB, greyscale, or CMYK from print software in the JPG; SGI supports greyscale (.bw), RGB (.rgb) or RGBA (.rgba), written here as 8-bit sRGB.
Metadata: the JPG can carry EXIF (camera, date, GPS), XMP, IPTC and an ICC profile in APP segments; SGI can carry only an 80-character image name in the header, but nothing is copied across.
About JPG
JPEG is the universal photo format. It compresses by discarding fine detail the eye is least sensitive to, which makes photos small but blurs sharp edges and text if pushed too far.
A JPEG starts with the bytes FF D8 and is a run of marker segments: APP1 carries EXIF and often a thumbnail, APP2 an ICC profile, DQT the quantization tables that decide the quality, and SOS the compressed scan, which ends at FF D9.
JPG files usually come from cameras, phones, scanners and almost every app that saves photos.
About SGI
SGI (also .rgb, .rgba, .bw) is the native image format of Silicon Graphics IRIX workstations, where much of 1990s 3D graphics and film work was done. It stores each colour channel as its own plane, uncompressed or run-length encoded.
An SGI file starts with the big-endian magic number 474 (01 DA), a storage byte (0 verbatim, 1 RLE), bytes per channel, dimensions and channel count in a 512-byte header. Channels are stored as separate planes and rows run from the bottom of the image up; RLE files add tables of row offsets and lengths.
When converting JPG to SGI makes sense
SGI is the better choice for legacy SGI and 3D pipelines, while JPG suits photographs that need to open anywhere.
SGI strengths: Lossless, with 8 or 16 bits per channel; Alpha channel support; Still read by 3D and VFX tools. Drawbacks to weigh: Obsolete outside legacy pipelines; Weak compression; No browser support.
Limitations
- JPEG artefacts already in the file, such as blocking near edges and smeared colour, are kept as pixels: a lossless target preserves them faithfully rather than removing them.
- Blender, GIMP, ImageMagick and Nuke read SGI files, but browsers and most photo apps do not.
More conversions
Related tools
Convert SGI to JPG in your browser, with transparency filled in a colour you pick. Batch, private, no uploads.
Convert JPG to PNG in your browser, ready for screenshots, logos, graphics and anything that needs transparency. Batch, private, no uploads.
Convert JPG to WebP in your browser, ready for images on websites and in apps. Batch, private, no uploads.
Convert JPG to AVIF in your browser, ready for maximum compression on modern websites. Batch, private, no uploads.
Convert JPG to HEIC in your browser, a HEIF file with JPEG compression inside. Batch, private, no uploads.
Convert JPG to GIF in your browser, ready for short animations and reactions that must play everywhere. Batch, private, no uploads.
Convert JPG to PDF in your browser, one PDF page per image. Batch, private, no uploads.
Convert JPG to SVG in your browser, traced into real vector paths. Batch, private, no uploads.
Frequently asked questions
Does converting JPG to SGI lose quality?
SGI is written losslessly, so the pixels are stored exactly as decoded. Artefacts already in the JPG stay, but nothing new is lost.
Which apps open SGI files?
Blender, GIMP, ImageMagick, Nuke, XnView and IrfanView. It does not open in web browsers.
Are my images uploaded anywhere?
No. Processing happens inside your browser with WebAssembly and Web Workers. The site only downloads the app code and codecs; your files never leave your device. You can confirm this with the live upload counter on the tool, or in your browser's network panel.
Can I process many files at once?
Yes. Drop a whole selection or folder. Files are processed in parallel on several worker threads, each result can be downloaded on its own, and everything can be saved as one ZIP.
Is it free? Is there a file limit or watermark?
It is free with no account, no watermark and no daily limit. The only limit is your device's memory: very large images (over roughly 100 megapixels) may be refused to keep the tab from crashing.