Free webp to jpg
Image MIME Reference
ACES

ACES Image Container File

image/aces
VS

JPEG XS Image (HEIF Container)

image/jxsi
JPEG-XS-(HEIF)

A complete technical comparison of ACES Image Container File and JPEG XS Image (HEIF Container) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature ACES JPEG-XS-(HEIF)
Transparency (Alpha) Yes Yes
Animation Support ✕ No ✕ No
Progressive Loading ✕ No ✕ No
HDR Support Yes Yes
EXIF Metadata ✕ No Yes
ICC Color Profile ✕ No Yes
ACES Image Container File
image/aces
Extension
.exr
Container OpenEXR (SMPTE ST 2065-4)
Compression Lossless / Uncompressed
Algorithm
PIZZIPRLEB44Uncompressed
Color Depth 16-bit (Half-float), 32-bit (Float)
Developed by Academy of Motion Picture Arts and Sciences (AMPAS) / SMPTE
Released 2013
Magic Bytes
76 2F 31 01
Full ACES reference →
JPEG XS Image (HEIF Container)
image/jxsi
Extension
.jxsi.jxs.hif
Container HEIF / ISOBMFF (ISO/IEC 23008-12)
Compression Lossy (Visually Lossless) / Mathematically Lossless
Algorithm
JPEG XS (ISO/IEC 21122-1)
Color Depth 8-bit, 10-bit, 12-bit, 14-bit, 16-bit
Developed by Joint Photographic Experts Group (JPEG)
Released 2019
Magic Bytes
XX XX XX XX 66 74 79 70 6A 78 73 69
Full JPEG-XS-(HEIF) reference →

Browser Support Comparison

Browser ACES JPEG-XS-(HEIF)
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
ACES

ACES Strengths

  • Industry standard for high-end visual effects, compositing, and color grading
  • Supports 16-bit half-float data, accurately capturing immense dynamic range without clipping
  • Standardized by SMPTE (ST 2065-4) to guarantee universal color interoperability across different post-production facilities
Limitations
  • Considerably larger file sizes than conventional consumer image formats
  • Completely unsupported in web browsers and most standard desktop viewers
  • Requires specialized compositing or color grading software to interpret and view the scene-linear data correctly
JPEG-XS-(HEIF)

JPEG-XS-(HEIF) Strengths

  • Provides sub-millisecond encoding and decoding latency while retaining visually lossless quality
  • Brings the extensive metadata, EXIF, XMP, and color-profiling capabilities of the HEIF container to JPEG XS
  • Allows grouping of multiple high-quality JPEG XS frames into a single collection file
Limitations
  • Zero web browser compatibility, limiting it entirely to professional and industrial hardware workflows
  • Extremely niche adoption compared to standard HEVC-based HEIC or raw JPEG XS codestreams
  • Requires custom parsing logic to extract the JPEG XS codestream from the HEIF boxes

When to choose which format

ACES
Use ACES when…
  • Visual Effects (VFX)
  • Digital Intermediate (DI)
  • Color Grading
  • Archival
JPEG-XS-(HEIF)
Use JPEG-XS-(HEIF) when…
  • Live Broadcast Infrastructure
  • Medical Imaging & Archival
  • Video over IP Networks
  • Automotive & Drone Systems
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