Free webp to jpg
Image MIME Reference
AVIF

AV1 Image File Format

image/avif
VS

Pentax Electronic File

image/x-pentax-pef
Pentax-PEF

A complete technical comparison of AV1 Image File Format and Pentax Electronic File — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

AVIF wins on browser support

Feature Support

Feature AVIF Pentax-PEF
Transparency (Alpha) Yes ✕ No
Animation Support Yes ✕ No
Progressive Loading ✕ No ✕ No
HDR Support Yes Yes
EXIF Metadata Yes Yes
ICC Color Profile Yes Yes
AV1 Image File Format
image/avif
Extension
.avif
Container HEIF / ISOBMFF
Compression AV1 Lossy / AV1 Lossless
Algorithm
AV1
Color Depth 8-bit, 10-bit, 12-bit
Developed by Alliance for Open Media (AOMedia)
Released 2019
Magic Bytes
XX XX XX XX 66 74 79 70 61 76 69 66
Full AVIF 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 AVIF Pentax-PEF
Chrome Chrome
✓ 85+
Firefox Firefox
✓ 93+
Safari Safari
✓ 16+
Edge Edge
✓ 121+
IE IE (Legacy)
AVIF

AVIF Strengths

  • Best-in-class compression — typically 20–50% smaller than WebP at equivalent quality
  • Native HDR and wide color gamut (BT.2020) support
  • Supports 8, 10, and 12-bit color depth
Limitations
  • Encoding is highly CPU-intensive — significantly slower than JPEG or WebP
  • Requires Edge 121+ (not supported in earlier Edge versions)
  • Limited support in native desktop image viewers
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

AVIF
Use AVIF when…
  • Next-Gen Websites
  • HDR Photography
  • High-Quality Web Images
Pentax-PEF
Use Pentax-PEF when…
  • Professional Digital Photography
  • Non-destructive Image Post-Processing
  • Pentax Camera Archival
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