Free webp to jpg
EN
Image MIME Reference
JPEG-XS-Sequence

JPEG XS Image Sequence (HEIF Container)

image/jxss
VS

Apple PICT Image

image/x-pict
PICT

A complete technical comparison of JPEG XS Image Sequence (HEIF Container) 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-Sequence 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 Sequence (HEIF Container)
image/jxss
Extension
.jxss.jxs
Container HEIF / ISOBMFF (ISO/IEC 23008-12)
Compression Lossy (Visually Lossless) / Mathematically Lossless
Algorithm
JPEG XS (ISO/IEC 21122-1)
Color Depth 8-bit, 10-bit, 12-bit, 14-bit, 16-bit
Developed by Joint Photographic Experts Group (JPEG)
Released 2019
Magic Bytes
XX XX XX XX 66 74 79 70 6A 78 73 73
Full JPEG-XS-Sequence reference →
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)
Full PICT reference →

Browser Support Comparison

Browser JPEG-XS-Sequence PICT
Chrome Chrome
✕ ✕
Firefox Firefox
✕ ✕
Safari Safari
✕ ✕
Edge Edge
✕ ✕
IE IE (Legacy)
✕ ✕
JPEG-XS-Sequence

JPEG-XS-Sequence Strengths

  • Provides sub-millisecond encoding and decoding latency across a video sequence while retaining visually lossless quality
  • Leverages the robust ISOBMFF track structures for accurate frame timing, audio synchronization, and metadata handling
  • Optimized for professional video production and IP broadcasting workflows
Limitations
  • Zero web browser compatibility, limiting its use entirely to professional and industrial hardware workflows
  • Compression ratios are significantly lower than consumer video codecs like HEVC or AV1
  • Extremely niche format that requires highly specialized broadcast hardware or custom software libraries to process
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-Sequence
Use JPEG-XS-Sequence when…
  • Live Broadcast Video Snippets
  • Medical Imaging Sequences
  • HDR Burst Photography Archiving
  • Automotive & Drone Video Storage
PICT
Use PICT when…
  • Classic Mac OS Clipboard Data
  • Legacy Macintosh Desktop Publishing (Aldus PageMaker, QuarkXPress)
  • 1980s/1990s Digital Clip Art

More comparisons

JPEG-XS-Sequence vs ACES → PICT vs ACES → JPEG-XS-Sequence vs APNG → PICT vs APNG → JPEG-XS-Sequence vs AVCI → PICT vs AVCI → JPEG-XS-Sequence vs AVCS → PICT vs AVCS → JPEG-XS-Sequence vs AVIF → PICT vs AVIF → All comparisons →
Share this comparison