Image MIME Reference
ACES
ACES Image Container File
image/aces
VS
Kodak Digital Camera Raw
image/x-kodak-dcr
Kodak-DCR
A complete technical comparison of ACES Image Container File and Kodak Digital Camera Raw — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | ACES | Kodak-DCR |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| 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
Kodak Digital Camera Raw
image/x-kodak-dcr
Extension
.dcr
Container
TIFF/EP
Compression
Uncompressed / Lossless JPEG
Algorithm
NoneLossless JPEG (ITU-T81)
Color Depth
12-bit (Per Channel)
Developed by
Eastman Kodak Company
Released
1998
Magic Bytes
49 49 2A 00 or 4D 4D 00 2A
Browser Support Comparison
| Browser | ACES | Kodak-DCR |
|---|---|---|
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✕ | ✕ |
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✕ | ✕ |
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✕ | ✕ |
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✕ | ✕ |
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✕ | ✕ |
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
Kodak-DCR
Kodak-DCR Strengths
- Preserves the full dynamic range and uncompressed raw sensor data captured by foundational professional digital cameras
- Utilizes the standard TIFF container structure, ensuring that open-source decoders like LibRaw can easily parse and interpret the files long after official vendor support has ended
Limitations
- Completely obsolete proprietary format tied to camera hardware that is no longer manufactured
- Shares the TIFF magic header, leading to widespread misidentification by automated MIME detection libraries
- Cannot be natively viewed in web browsers or standard operating system image viewers without specialized codecs
When to choose which format
ACES
Use ACES when…
- Visual Effects (VFX)
- Digital Intermediate (DI)
- Color Grading
- Archival
Kodak-DCR
Use Kodak-DCR when…
- Vintage Professional Digital Photography (Kodak DCS series)
- Non-destructive Image Post-Processing
- Raw Imaging Archival