Free webp to jpg
Image MIME Reference
APNG

Animated Portable Network Graphics

image/vnd.mozilla.apng
VS

Sony SR2 Raw Image

image/x-sony-sr2
Sony-SR2

A complete technical comparison of Animated Portable Network Graphics and Sony SR2 Raw Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

APNG wins on browser support

Feature Support

Feature APNG Sony-SR2
Transparency (Alpha) Yes ✕ No
Animation Support Yes ✕ No
Progressive Loading Yes ✕ No
HDR Support ✕ No Yes
EXIF Metadata Yes Yes
ICC Color Profile Yes Yes
Animated Portable Network Graphics
image/vnd.mozilla.apng
Extension
.apng.png
Container PNG Chunk Stream
Compression Deflate (Lossless)
Algorithm
Deflate (zlib)
Color Depth 8-bit (Indexed), 24-bit (TrueColor), 32-bit (RGBA)
Developed by Mozilla Corporation (Stuart Parmenter & Vladimir Vukićević)
Released 2004
Magic Bytes
89 50 4E 47 0D 0A 1A 0A
Full APNG reference →
Sony SR2 Raw Image
image/x-sony-sr2
Extension
.sr2
Container TIFF-based (Proprietary)
Compression Uncompressed / Sony Proprietary Lossless
Algorithm
NoneSony Proprietary Lossless
Color Depth 12-bit (Per Channel)
Developed by Sony Corporation
Released 2005
Magic Bytes
49 49 2A 00
Full Sony-SR2 reference →

Browser Support Comparison

Browser APNG Sony-SR2
Chrome Chrome
✓ 59
Firefox Firefox
✓ 3
Safari Safari
✓ 8
Edge Edge
✓ 79
IE IE (Legacy)
APNG

APNG Strengths

  • Supports 8-bit alpha transparency, completely solving the ugly 'white halo' problem inherent to GIFs
  • Gracefully degrades; viewers that do not support APNG will render a perfectly valid, static PNG of the first frame
  • Provides lossless compression that retains absolute pixel-perfect quality for UI elements and line art
Limitations
  • Because it relies on lossless Deflate compression, file sizes for complex, video-like animations can be massive compared to lossy formats like WebP or AVIF
  • Was initially rejected by the official PNG group, delaying its adoption for nearly a decade
  • Lacks native hardware decoding acceleration, unlike video-based animated formats (like MP4 or WebM)
Sony-SR2

Sony-SR2 Strengths

  • Retains raw, unprocessed sensor data from legacy cameras, allowing modern raw processors to extract vastly superior image quality than what was possible in 2005
  • Utilizes a standard TIFF container structure, ensuring that community-maintained open-source decoding libraries (like LibRaw) can easily parse and maintain support for it indefinitely
Limitations
  • Completely obsolete format that has not been utilized in a new camera release in over a decade
  • MIME detection via magic bytes is unreliable due to TIFF header spoofing, requiring deeper EXIF inspection
  • Cannot be natively viewed in web browsers or standard operating system image viewers without specialized decoders

When to choose which format

APNG
Use APNG when…
  • High-Quality Web Animations
  • Stickers (Apple iMessage, LINE, Discord)
  • UI Loaders with Alpha Transparency
  • GIF Replacement
Sony-SR2
Use Sony-SR2 when…
  • Legacy Sony Cyber-shot/Alpha Photography
  • Non-destructive Image Post-Processing
  • Raw Imaging Archival
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