Image MIME Reference
JPEG-XS
JPEG XS Image
image/jxs
VS
Apple PICT Image
image/x-pict
PICT
A complete technical comparison of JPEG XS Image and Apple PICT Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | JPEG-XS | PICT |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | Yes | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | Yes | ✕ No |
| EXIF Metadata | Yes | ✕ No |
| ICC Color Profile | Yes | ✕ No |
JPEG XS Image
image/jxs
Extension
.jxs
Container
ISOBMFF (ISO/IEC 21122-3) or Raw Codestream
Compression
Lossy (Visually Lossless) / Mathematically Lossless
Algorithm
JPEG XS (Low-complexity wavelet transform)
Color Depth
8-bit, 10-bit, 12-bit, 14-bit, 16-bit
Developed by
Joint Photographic Experts Group (JPEG) / intoPIX
Released
2019
Magic Bytes
FF 10 (Codestream) / XX XX XX XX 66 74 79 70 6A 78 73 20 (ISOBMFF)
Apple PICT Image
image/x-pict
Extension
.pict.pct.pic
Container
QuickDraw Metafile
Compression
Uncompressed / Run-Length Encoding (RLE) / QuickTime Compressors (JPEG, SMC)
Algorithm
Apple PackBits (RLE)QuickTime Image Compression Manager (ICM)
Color Depth
1-bit, 2-bit, 4-bit, 8-bit (Indexed), 16-bit (High Color), 24-bit (True Color), 32-bit (RGBA)
Developed by
Apple Computer, Inc.
Released
1984
Magic Bytes
None (Requires offset parsing, e.g., 00 11 02 FF at byte 522)
Browser Support Comparison
| Browser | JPEG-XS | PICT |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
JPEG-XS
JPEG-XS Strengths
- Provides sub-millisecond encoding/decoding latency, essential for live production and gaming
- Extremely lightweight, requiring very little CPU, GPU, or FPGA memory to process
- Replaces uncompressed video links (like SDI or HDMI) over standard Ethernet networks with visually lossless quality
Limitations
- Compression ratios are typically much lower (between 2:1 and 10:1) compared to heavy codecs like HEVC or AV1
- Zero support in web browsers or standard consumer devices
- Primarily licensed to hardware manufacturers and professional software ecosystems
PICT
PICT Strengths
- Incredibly versatile for its time, allowing a single file to cleanly scale text and vector shapes while simultaneously housing raster photos
- Served as the flawless universal clipboard format for the classic Mac OS, enabling seamless copy/pasting between wildly different applications
Limitations
- Deeply tied to Apple's legacy QuickDraw graphics architecture, making it exceptionally difficult to write accurate third-party parsers on modern operating systems
- Lack of a standard magic header makes file detection unreliable without seeking 522 bytes deep into the file
- Completely unsupported in modern web environments and discontinued by Apple itself
When to choose which format
JPEG-XS
Use JPEG-XS when…
- Live Video Broadcasting (SMPTE ST 2110)
- Video over IP Networks
- Virtual Reality / Augmented Reality (VR/AR)
- Automotive & Drone Cameras
PICT
Use PICT when…
- Classic Mac OS Clipboard Data
- Legacy Macintosh Desktop Publishing (Aldus PageMaker, QuarkXPress)
- 1980s/1990s Digital Clip Art