Free webp to jpg
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Image MIME Reference
APNG

Animated Portable Network Graphics

image/vnd.mozilla.apng
VS

Sony SRF Raw Image

image/x-sony-srf
Sony-SRF

A complete technical comparison of Animated Portable Network Graphics and Sony SRF 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-SRF
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 SRF Raw Image
image/x-sony-srf
Extension
.srf
Container TIFF-based (Proprietary)
Compression Uncompressed
Algorithm
None
Color Depth 12-bit (Per Channel)
Developed by Sony Corporation
Released 2003
Magic Bytes
49 49 2A 00
Full Sony-SRF reference →

Browser Support Comparison

Browser APNG Sony-SRF
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-SRF

Sony-SRF Strengths

  • Retains perfectly raw, unprocessed sensor data from legacy early-2000s cameras, allowing modern raw processors to extract much better dynamic range and color than the camera's original internal JPEG engine could
  • Utilizes a standard TIFF container structure, ensuring broad compatibility with community-maintained open-source decoding libraries like LibRaw
Limitations
  • Completely obsolete format that has long been abandoned in favor of ARW
  • MIME detection via magic bytes is unreliable due to TIFF header spoofing, requiring deeper EXIF inspection for accurate routing
  • 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-SRF
Use Sony-SRF when…
  • Legacy Sony Cyber-shot Photography
  • Non-destructive Image Post-Processing
  • Early 2000s Raw Imaging Archival

More comparisons

APNG vs ACES → Sony-SRF vs ACES → APNG vs AVCI → Sony-SRF vs AVCI → APNG vs AVCS → Sony-SRF vs AVCS → APNG vs AVIF → Sony-SRF vs AVIF → All comparisons →
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