Image MIME Reference
AVCI
AVC Image (HEIF Container)
image/avci
VS
Kodak K25 Raw Image
image/x-kodak-k25
Kodak-K25
A complete technical comparison of AVC Image (HEIF Container) and Kodak K25 Raw Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | AVCI | Kodak-K25 |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | Yes | Yes |
| EXIF Metadata | Yes | Yes |
| ICC Color Profile | Yes | ✕ No |
AVC Image (HEIF Container)
image/avci
Extension
.avci.hif
Container
HEIF / ISOBMFF (ISO/IEC 14496-12)
Compression
Lossy / Lossless
Algorithm
AVC (Advanced Video Coding / H.264)
Color Depth
8-bit, 10-bit, 12-bit
Developed by
Moving Picture Experts Group (MPEG) / ISO/IEC JTC 1
Released
2015
Magic Bytes
XX XX XX XX 66 74 79 70 61 76 63 69
Kodak K25 Raw Image
image/x-kodak-k25
Extension
.k25
Container
Proprietary Kodak Raw (TIFF-based variant)
Compression
Uncompressed / Proprietary Lossless
Algorithm
Proprietary Kodak Compression
Color Depth
10-bit, 12-bit (Per Channel)
Developed by
Eastman Kodak Company
Released
1996
Magic Bytes
Varies (Often resembles TIFF header 49 49 2A 00 or requires proprietary parsing)
Browser Support Comparison
| Browser | AVCI | Kodak-K25 |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
AVCI
AVCI Strengths
- Shares the robust, flexible HEIF container architecture that allows for rich metadata, HDR, and depth maps.
- Backed by the highly ubiquitous AVC (H.264) codec, which is widely supported in hardware decoding.
- Supports rectangular cropping and rotation metadata without needing to re-encode the pixel data.
Limitations
- No native support within web browsers for HTML rendering.
- Inferior compression efficiency when compared to newer container formats like HEIC (HEVC) or AVIF (AV1).
- Easily confused with HEIC and AVIF, which use the same base ISOBMFF container.
Kodak-K25
Kodak-K25 Strengths
- Historically significant format tied to the first digital camera to adopt CompactFlash memory
- Preserves original raw sensor data, allowing modern demosaicing algorithms (via LibRaw) to extract much better image quality than 1996-era software could
Limitations
- Completely obsolete and deeply proprietary, lacking modern raw format features found in DNG
- Cannot be natively viewed in web browsers or standard operating system image viewers without specialized decoders
- Subject to misidentification by automated MIME detection libraries due to structural similarities with standard TIFFs
When to choose which format
AVCI
Use AVCI when…
- Digital Photography
- Camera Capture
- Archival Storage
Kodak-K25
Use Kodak-K25 when…
- Vintage Digital Photography Archival
- Kodak DC25 Camera Restorations
- Historical Imaging Research