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Image MIME Reference
JPM

JPEG 2000 Compound Image File Format

image/jpm
VS

Apple PICT Image

image/x-pict
PICT

A complete technical comparison of JPEG 2000 Compound Image File Format and Apple PICT Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature JPM PICT
Transparency (Alpha) Yes Yes
Animation Support ✕ No ✕ No
Progressive Loading Yes ✕ No
HDR Support ✕ No ✕ No
EXIF Metadata Yes ✕ No
ICC Color Profile Yes ✕ No
JPEG 2000 Compound Image File Format
image/jpm
Extension
.jpm.jpgm
Container ISOBMFF / JPM (ISO/IEC 15444-6)
Compression Lossy / Lossless / Mixed Raster Content (MRC)
Algorithm
JPEG 2000JBIG2JPEGMMR
Color Depth 1-bit (Text/Masks), 8-bit, 16-bit, 24-bit
Developed by Joint Photographic Experts Group (JPEG)
Released 2003
Magic Bytes
00 00 00 0C 6A 50 20 20 0D 0A 87 0A ... 66 74 79 70 6A 70 6D 20
Full JPM 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 JPM PICT
Chrome Chrome
✕ ✕
Firefox Firefox
✕ ✕
Safari Safari
✕ ✕
Edge Edge
✕ ✕
IE IE (Legacy)
✕ ✕
JPM

JPM Strengths

  • Highly optimized for scanned documents, drastically reducing file sizes without sacrificing the readability of text or the quality of embedded photos
  • Supports multi-page documents within a single file
  • Object-based architecture allows for complex layout representation and independent extraction of elements
Limitations
  • Failed to achieve widespread adoption, largely being overshadowed by PDF/A and DjVu
  • Zero native web browser compatibility
  • Requires complex, specialized software to properly encode and decode the multi-layered MRC structure
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

JPM
Use JPM when…
  • Scanned Document Archiving
  • Mixed Raster Content (MRC) Imaging
  • Digital Libraries
PICT
Use PICT when…
  • Classic Mac OS Clipboard Data
  • Legacy Macintosh Desktop Publishing (Aldus PageMaker, QuarkXPress)
  • 1980s/1990s Digital Clip Art

More comparisons

JPM vs ACES → PICT vs ACES → JPM vs APNG → PICT vs APNG → JPM vs AVCI → PICT vs AVCI → JPM vs AVCS → PICT vs AVCS → JPM vs AVIF → PICT vs AVIF → All comparisons →
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