Image MIME Reference
JPX
JPEG 2000 Part 2 (Extended)
image/jpx
VS
Adobe Photoshop Document
image/vnd.adobe.photoshop
PSD
A complete technical comparison of JPEG 2000 Part 2 (Extended) and Adobe Photoshop Document — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | JPX | PSD |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | Yes | Yes |
| Progressive Loading | Yes | ✕ No |
| HDR Support | Yes | Yes |
| EXIF Metadata | Yes | Yes |
| ICC Color Profile | Yes | Yes |
JPEG 2000 Part 2 (Extended)
image/jpx
Extension
.jpx.jpf
Container
ISOBMFF / JPX (ISO/IEC 15444-2)
Compression
Lossy / Lossless
Algorithm
Discrete Wavelet Transform (DWT)
Color Depth
8-bit, 16-bit, 32-bit, 38-bit
Developed by
Joint Photographic Experts Group (JPEG)
Released
2002
Magic Bytes
00 00 00 0C 6A 50 20 20 0D 0A 87 0A ... 66 74 79 70 6A 70 78 20
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 | JPX | PSD |
|---|---|---|
|
|
✕ | ✕ |
|
|
✕ | ✕ |
|
|
✕ | ✕ |
|
|
✕ | ✕ |
|
|
✕ | ✕ |
JPX
JPX Strengths
- Removes the color space limitations of baseline JP2, adding native support for CMYK, CIE Lab, and custom vendor color spaces
- Supports multiple codestreams in a single file, allowing for rich compositing and animation
- Enables fragmented files where image data and metadata can reside in separate physical files via data references
Limitations
- Extremely complex specification makes full software implementation rare, leading to compatibility issues
- Zero web browser support, rendering it unsuitable for public internet distribution
- Often overkill for standard imaging tasks where baseline JP2 or modern alternatives like AVIF suffice
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
JPX
Use JPX when…
- Prepress & Commercial Printing (CMYK)
- Geospatial Data
- Archival Preservation
- Medical Imaging
PSD
Use PSD when…
- Professional Photo Retouching
- Digital Painting and Illustration
- UI/UX Design Workflows
- Graphic Design and Print Production