Free webp to jpg
EN
Image MIME Reference
Generic-RAW

Digital Camera Raw (Generic Linux MIME)

image/x-dcraw
VS

Panasonic RAW Image

image/x-panasonic-raw
Panasonic-RAW-(RW2)

A complete technical comparison of Digital Camera Raw (Generic Linux MIME) and Panasonic RAW Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature Generic-RAW Panasonic-RAW-(RW2)
Transparency (Alpha) ✕ No ✕ No
Animation Support ✕ No ✕ No
Progressive Loading ✕ No ✕ No
HDR Support Yes Yes
EXIF Metadata Yes Yes
ICC Color Profile Yes Yes
Digital Camera Raw (Generic Linux MIME)
image/x-dcraw
Extension
.raw
Container Varies (Predominantly TIFF/EP)
Compression Lossless / Uncompressed
Algorithm
Varies (Often Lossless JPEG ITU-T81 or uncompressed)
Color Depth 12-bit, 14-bit, 16-bit
Developed by freedesktop.org (MIME mapping) / Dave Coffin (dcraw tool)
Released 1997
Magic Bytes
Varies by vendor format
Full Generic-RAW reference →
Panasonic RAW Image
image/x-panasonic-raw
Extension
.raw.rw2
Container TIFF-based (Proprietary)
Compression Uncompressed / Panasonic Proprietary Lossless
Algorithm
NoneProprietary Lossless
Color Depth 12-bit (Per Channel), 14-bit (Per Channel), 16-bit (Per Channel - High-res mode)
Developed by Panasonic Corporation
Released 2004
Magic Bytes
Older RAW: 49 49 2A 00 | Newer RW2: 49 49 55 00
Full Panasonic-RAW-(RW2) reference →

Browser Support Comparison

Browser Generic-RAW Panasonic-RAW-(RW2)
Chrome Chrome
✕ ✕
Firefox Firefox
✕ ✕
Safari Safari
✕ ✕
Edge Edge
✕ ✕
IE IE (Legacy)
✕ ✕
Generic-RAW

Generic-RAW Strengths

  • Provides a unified, highly useful catch-all MIME type for application developers who just need to know if a file is a raw image, rather than tracking 50+ individual camera extensions
  • Deeply integrated into the Linux desktop ecosystem, ensuring file manager thumbnails work seamlessly via tools like ufraw-thumbnailer
Limitations
  • Not an official IANA standard
  • Can cause conflicts where standard TIFF files are misidentified as raw camera data by over-aggressive MIME sniffers
  • The underlying 'dcraw' tool was abandoned by its creator in 2018 (though its successor, LibRaw, continues to maintain the ecosystem)
Panasonic-RAW-(RW2)

Panasonic-RAW-(RW2) Strengths

  • Retains maximum sensor data, allowing significant recovery of highlights and shadows compared to in-camera JPEGs
  • Modern RW2 files embed proprietary lens correction profiles (distortion, vignetting, chromatic aberration) that raw converters can automatically apply
  • The unique 'IIU' signature on RW2 files makes programmatic identification extremely reliable compared to other TIFF-spoofing raw formats
Limitations
  • Proprietary format requires continuous updates to third-party processing engines whenever Panasonic releases a new Lumix camera
  • Produces very large file sizes, particularly when using Panasonic's High-Resolution multi-shot modes
  • Cannot be directly embedded into web pages or used in standard HTML/CSS contexts

When to choose which format

Generic-RAW
Use Generic-RAW when…
  • Linux Desktop File Associations (GNOME/KDE)
  • Thumbnail Generation for Raw Images (UFRaw/LibRaw)
  • Server-side Image Processing Fallbacks
Panasonic-RAW-(RW2)
Use Panasonic-RAW-(RW2) when…
  • Professional Digital Photography
  • Non-destructive Image Post-Processing
  • High Dynamic Range (HDR) Lumix Archival

More comparisons

Generic-RAW vs ACES → Panasonic-RAW-(RW2) vs ACES → Generic-RAW vs APNG → Panasonic-RAW-(RW2) vs APNG → Generic-RAW vs AVCI → Panasonic-RAW-(RW2) vs AVCI → Generic-RAW vs AVCS → Panasonic-RAW-(RW2) vs AVCS → Generic-RAW vs AVIF → Panasonic-RAW-(RW2) vs AVIF → All comparisons →
Share this comparison