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libopenraw is an ongoing project to provide a free software implementation for camera RAW files decoding. One of the main reason is that dcraw is not suited for easy integration into applications, and there is a need for an easy to use API to build free software digital image processing application.

It also has the goal to address missing feature from dcraw like meta-data decoding and easy thumbnail extraction.


This is currently a work in progress. The only code available is in git. Once a release will be made, it will be announced here.

Planned feature

  • Support for as much file format as possible. NEF, CRW, CR2 and DNG obviously as they are the most common (well DNG not really but it is "standard").
  • Modular low level API that allow:
    • Identify the file
    • Parse the file
    • Extract the meta-data and the previews
    • Allow processing the RAW data in different way, including having them extracted for an application custom processor.
  • High level API that allow:
    • Provide and standard thumbnail - Done
    • Preprocess the file using standard parameters
    • Extract the metadata as EXIF (and XMP)
    • Convert to a DNG file


  • Get a basic thumbnail extractor for CR2, CRW, DNG, NEF, ORF - Done
  • Get a basic metadata extractor for CR2, CRW, DNG, NEF, ORF
  • Get a basic RAW processor for CR2, CRW, DNG, NEF, ORF

Getting code from git

                 * Anonymous git 
                                         * `git clone git://` 
                 * For developers (needs authorization). 
                                         * Get a username if you don't have one: See <a href=""></a> for details. 
                                         * Check out the tree: `git clone git+ssh://` 

Links to documentation

Given how manufacturer document these formats, we have to reverse-engineer or use documentation issued from reverse engineering.


  • dcraw the current reference implementation for RAW decoding.
  • jrawio a Java library that implements RAW image decoding

File format



-- ?HubertFiguiere


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