Free webp to jpg
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Image MIME Reference
APNG

Animated Portable Network Graphics

image/vnd.mozilla.apng
VS

Pentax Electronic File

image/x-pentax-pef
Pentax-PEF

A complete technical comparison of Animated Portable Network Graphics and Pentax Electronic File — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

APNG wins on browser support

Feature Support

Feature APNG Pentax-PEF
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 →
Pentax Electronic File
image/x-pentax-pef
Extension
.pef
Container TIFF-based (Proprietary)
Compression Uncompressed / Proprietary Lossless
Algorithm
NonePentax Proprietary Lossless
Color Depth 12-bit (Per Channel), 14-bit (Per Channel)
Developed by Pentax (now Ricoh Imaging Company, Ltd.)
Released 2003
Magic Bytes
49 49 2A 00 (Little-endian) or 4D 4D 00 2A (Big-endian)
Full Pentax-PEF reference →

Browser Support Comparison

Browser APNG Pentax-PEF
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)
Pentax-PEF

Pentax-PEF Strengths

  • Retains absolute maximum sensor data, enabling massive shadow recovery and highlight protection compared to compressed in-camera JPEGs
  • White balance and sharpening are saved as metadata instructions rather than 'baked in', meaning they can be perfectly adjusted in post-production
  • Utilizes the standard TIFF container structure, making it relatively straightforward for open-source software like LibRaw to parse
Limitations
  • Proprietary format requires continuous updates to third-party processing software whenever Pentax releases a new camera model (unlike the open DNG format)
  • Produces very large file sizes compared to standard web formats
  • Cannot be directly embedded into web pages or used in standard HTML/CSS contexts

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
Pentax-PEF
Use Pentax-PEF when…
  • Professional Digital Photography
  • Non-destructive Image Post-Processing
  • Pentax Camera Archival

More comparisons

APNG vs ACES → Pentax-PEF vs ACES → APNG vs AVCI → Pentax-PEF vs AVCI → APNG vs AVCS → Pentax-PEF vs AVCS → APNG vs AVIF → Pentax-PEF vs AVIF → All comparisons →
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