Free webp to jpg
Image MIME Reference
AVIF

AV1 Image File Format

image/avif
VS

Silicon Graphics Image

image/sgi
SGI

A complete technical comparison of AV1 Image File Format and Silicon Graphics Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

AVIF wins on browser support

Feature Support

Feature AVIF SGI
Transparency (Alpha) Yes Yes
Animation Support Yes ✕ No
Progressive Loading ✕ No ✕ No
HDR Support Yes ✕ No
EXIF Metadata Yes ✕ No
ICC Color Profile Yes ✕ No
AV1 Image File Format
image/avif
Extension
.avif
Container HEIF / ISOBMFF
Compression AV1 Lossy / AV1 Lossless
Algorithm
AV1
Color Depth 8-bit, 10-bit, 12-bit
Developed by Alliance for Open Media (AOMedia)
Released 2019
Magic Bytes
XX XX XX XX 66 74 79 70 61 76 69 66
Full AVIF reference →
Silicon Graphics Image
image/sgi
Extension
.sgi.rgb.rgba.bw.int.inta
Container SGI Image Format
Compression Uncompressed / Lossless (Run-Length Encoding)
Algorithm
RLENone
Color Depth 8-bit, 16-bit (Per Channel)
Developed by Paul Haeberli (Silicon Graphics)
Released 1990
Magic Bytes
01 DA
Full SGI reference →

Browser Support Comparison

Browser AVIF SGI
Chrome Chrome
✓ 85+
Firefox Firefox
✓ 93+
Safari Safari
✓ 16+
Edge Edge
✓ 121+
IE IE (Legacy)
AVIF

AVIF Strengths

  • Best-in-class compression — typically 20–50% smaller than WebP at equivalent quality
  • Native HDR and wide color gamut (BT.2020) support
  • Supports 8, 10, and 12-bit color depth
Limitations
  • Encoding is highly CPU-intensive — significantly slower than JPEG or WebP
  • Requires Edge 121+ (not supported in earlier Edge versions)
  • Limited support in native desktop image viewers
SGI

SGI Strengths

  • Pioneered multi-channel and 16-bit per channel imaging capabilities required for high-end 1990s visual effects
  • Extremely robust and simple header structure
  • Reliable Run-Length Encoding provided solid lossless compression for flat-shaded 3D renders
Limitations
  • Completely obsolete for modern web and application development
  • Zero native web browser compatibility
  • Largely replaced by TIFF and OpenEXR in modern professional VFX and 3D pipelines

When to choose which format

AVIF
Use AVIF when…
  • Next-Gen Websites
  • HDR Photography
  • High-Quality Web Images
SGI
Use SGI when…
  • Legacy 3D Animation & VFX
  • Silicon Graphics IRIX Workflows
  • Historical CGI Archiving
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