Free webp to jpg
Image MIME Reference
Canon-CRW

Canon Raw Format

image/x-canon-crw
VS

JPEG Network Graphics

image/x-jng
JNG

A complete technical comparison of Canon Raw Format and JPEG Network Graphics — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature Canon-CRW JNG
Transparency (Alpha) ✕ No Yes
Animation Support ✕ No ✕ No
Progressive Loading ✕ No Yes
HDR Support Yes ✕ No
EXIF Metadata Yes Yes
ICC Color Profile ✕ No Yes
Canon Raw Format
image/x-canon-crw
Extension
.crw
Container CIFF (Camera Image File Format)
Compression Lossless JPEG (ITU-T81)
Algorithm
Lossless JPEG
Color Depth 10-bit (Per Channel), 12-bit (Per Channel)
Developed by Canon Inc.
Released 1998
Magic Bytes
49 49 1A 00 00 00 (Header) / 48 45 41 50 43 43 44 52 (HEAPCCDR signature near end)
Full Canon-CRW reference →
JPEG Network Graphics
image/x-jng
Extension
.jng
Container PNG-style Chunk Structure (JHDR, JDAT, IDAT, IEND)
Compression Lossy (JPEG/DCT for color) / Lossless (Deflate for alpha mask)
Algorithm
JPEG (Discrete Cosine Transform)Deflate (LZ77)
Color Depth 8-bit, 12-bit, 24-bit (RGB), 32-bit (RGBA)
Developed by MNG Development Group (Glenn Randers-Pehrson et al.)
Released 2001
Magic Bytes
8B 4A 4E 47 0D 0A 1A 0A
Full JNG reference →

Browser Support Comparison

Browser Canon-CRW JNG
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
Canon-CRW

Canon-CRW Strengths

  • Preserves original raw sensor data from foundational early digital SLR cameras, allowing for modern noise reduction and demosaicing algorithms to extract better images than software could in 2003
  • Files are remarkably small (often 6-8 MB) compared to modern 40MB+ raw files due to the lower megapixel count of early sensors
Limitations
  • Completely obsolete and utilizes the idiosyncratic CIFF structure rather than the modern, standardized TIFF/EP structure
  • Cannot be natively viewed in web browsers or standard operating system image viewers without specialized codecs
  • Less robust metadata support compared to modern CR2 or CR3 formats
JNG

JNG Strengths

  • Solved a massive technical hurdle in the early 2000s by combining high-compression lossy photographic data with crisp, 8-bit alpha transparency
  • Utilized the highly robust, extensible chunk-based architecture of the PNG format
  • Provided an excellent, bandwidth-saving alternative to massive 32-bit transparent PNGs for web design
Limitations
  • Failed to achieve critical mass; browser vendors largely abandoned the MNG/JNG standard due to implementation complexity
  • Completely obsolete today, having been superseded by natively supported, superior formats like WebP, AVIF, and HEIC
  • Decoding requires a hybrid engine that can parse PNG chunks while simultaneously decoding a JPEG stream and a Deflate stream, complicating software support

When to choose which format

Canon-CRW
Use Canon-CRW when…
  • Historical Digital Photography (2000-2004)
  • Non-destructive Image Post-Processing
  • Raw Imaging Archival
JNG
Use JNG when…
  • Embedded frames in MNG animations
  • Historical web graphics requiring lossy compression with transparency
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