Image MIME Reference
HEJ2K
JPEG 2000 Image (HEIF Container)
image/hej2k
VS
Adobe Photoshop Document
image/vnd.adobe.photoshop
PSD
A complete technical comparison of JPEG 2000 Image (HEIF Container) and Adobe Photoshop Document — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | HEJ2K | PSD |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | ✕ No | Yes |
| Progressive Loading | Yes | ✕ No |
| HDR Support | Yes | Yes |
| EXIF Metadata | Yes | Yes |
| ICC Color Profile | Yes | Yes |
JPEG 2000 Image (HEIF Container)
image/hej2k
Extension
.hej2
Container
HEIF / ISOBMFF (ISO/IEC 15444-16)
Compression
Lossy / Lossless
Algorithm
JPEG 2000HTJ2K
Color Depth
8-bit, 10-bit, 12-bit, 16-bit
Developed by
ISO/IEC JTC 1 / ITU-T
Released
2019
Magic Bytes
XX XX XX XX 66 74 79 70 6A 32 6B 69
Adobe Photoshop Document
image/vnd.adobe.photoshop
Extension
.psd.psb.pdd
Container
Adobe Photoshop Document (PSD/PSB)
Compression
Uncompressed / RLE (Run-Length Encoding) / ZIP
Algorithm
RLEZIP (with or without prediction)None
Color Depth
1-bit (Bitmap), 8-bit, 16-bit, 32-bit (Float/HDR)
Developed by
Adobe Systems
Released
1990
Magic Bytes
38 42 50 53
Browser Support Comparison
| Browser | HEJ2K | PSD |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
HEJ2K
HEJ2K Strengths
- Brings the extensive capabilities of the HEIF container (like EXIF/XMP, thumbnails, and depth maps) to JPEG 2000
- Supports mathematically lossless compression via wavelet transformation
- High scalability and progressive decoding out of the box
Limitations
- Extremely limited software support outside of niche industries
- Zero native compatibility with web browsers
- High computational complexity compared to simpler formats like JPEG or PNG
PSD
PSD Strengths
- The undisputed global standard for layered raster graphics and non-destructive image editing
- Supports incredibly complex compositions combining raster data, vector shapes, live text, and adjustment layers
- Full support for advanced color spaces (CMYK, Lab, multi-channel) and 32-bit floating-point HDR workflows
Limitations
- Proprietary format: while the specification is published, complete feature-parity is rarely achieved by third-party software (e.g., smart objects and complex layer styles often break)
- Files can reach enormous sizes (gigabytes) due to the preservation of unflattened, high-resolution layer data
- Zero support for native rendering in web browsers or standard mobile image viewers
When to choose which format
HEJ2K
Use HEJ2K when…
- Medical Imaging
- Geospatial Data
- Scientific Archiving
PSD
Use PSD when…
- Professional Photo Retouching
- Digital Painting and Illustration
- UI/UX Design Workflows
- Graphic Design and Print Production