Free webp to jpg
EN
Image MIME Reference
HEIC

High Efficiency Image Container

image/heic
VS

Silicon Graphics Image

image/sgi
SGI

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

HEIC wins on browser support

Feature Support

Feature HEIC 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
High Efficiency Image Container
image/heic
Extension
.heic
Container HEIF / ISOBMFF
Compression Lossy / Lossless
Algorithm
HEVC (H.265)
Color Depth 8-bit, 10-bit, 12-bit, 16-bit
Developed by MPEG (Standard) / Apple (Adoption)
Released 2017
Magic Bytes
XX XX XX XX 66 74 79 70 68 65 69 63
Full HEIC 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 HEIC SGI
Chrome Chrome
✕ ✕
Firefox Firefox
✕ ✕
Safari Safari
✓ 11+
 ✕
Edge Edge
✕ ✕
IE IE (Legacy)
✕ ✕
HEIC

HEIC Strengths

  • Exceptional compression efficiency — stores images at roughly half the file size of JPEG with equal or better visual quality
  • Natively supports modern photography features like depth maps, 16-bit color, HDR, and alpha channel transparency
  • Can store image bursts, focal stacks, and animations (Live Photos) within a single file
Limitations
  • Heavily encumbered by software patents, leading to very poor adoption outside the Apple ecosystem
  • Not supported by standard web browsers (except Safari), requiring server-side or client-side conversion for web delivery
  • Windows requires downloading a separate (often paid) extension from the Microsoft Store to view natively
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

HEIC
Use HEIC when…
  • iOS / iPhone Photography
  • macOS Ecosystem
  • High-Quality Image Archiving
SGI
Use SGI when…
  • Legacy 3D Animation & VFX
  • Silicon Graphics IRIX Workflows
  • Historical CGI Archiving

More comparisons

HEIC vs ACES → SGI vs ACES → HEIC vs APNG → SGI vs APNG → HEIC vs AVCI → SGI vs AVCI → HEIC vs AVCS → SGI vs AVCS → HEIC vs AVIF → SGI vs AVIF → All comparisons →
Share this comparison