This is a simple multi-threaded command line util that will recursively find image and video files, generating thumbnails for producing an index.html to allow easy browsing. Generated index will link to found files and can (using EXIF data) group equivalant files (ie a RAW file and a generated jpg) together under one image.

The intended use is for cataloguing large collections of images (particularly RAW files) to provide a single index in the form of a index.html; avoid the need for traditional file browsers to attempt to generate it's own thumbnails. This is particularly suited for DVD backups where the thumbnails (ie Windows .thumbs/ dirs) cannot be generated, with the generated index and catalogue being genreated and burned to the same backup. Instead of browsing the individual directories on the DVD (that would potentially cause redundant reads of each file to generate/extract thumbnails to display), we can browse the index.html and click through to required files.

For (Nikon NEF/Canon CR2/Fuji RAF/DNG) RAW files, the tool will extract the largest embedded thumbnails from the RAW file to generate thumbnail.

The (default) generated output is javascript file containing a JSON object of the scan results; a corresponding set of html/js/css exists that will render the results using justified gallery - navigation between index directories (via j/k or left/right arrows) and (XMP) rated files can be display-toggled 0-5.

# produces data.js
$ imgcat -t ./tn photos/2019-*

# obtain HTML after index'ing and thumb generation
$ cp -r <imgcat>/html/* .

# view index.html

To recognise other RAW formats, supported by Exiv2, update main and DFLT_EXTNS along with ImgExifParser.cc and the block that assigns data.type = ImgData::EMBD_PREVIEW

Sample RAW files available https://rawsamples.ch/index.php/en/

Command line util to extract largest thumbnail from (Nikon) RAW files; adds functionality not available in exiv2 or exiftool in that this tool can extract the thumbnail and perform colour space conversions (Adobe to sRGB) and also resizing of the images before writing to disk

Requires ImageMagick, exiv2 and SampleICC (local copy available) and ffmpegthumbnailer and libavformat (from ffmpeg) development libraries. If you are building ImageMagick from source, you should include delegates for:

• jpg
• xml (exif)
• lcms (NEF)
• png
• tiff (NEF)

If your distribution/host does not have SampleICC (ie Fedora) you can compile the one in this repo. I would build this locally as a static archive

git clone ... /tmp/imgcat

gzip -d < contrib/SampleICC-1.6.8.tar.gz | tar xf -
cd SampleICC-1.6.8 && ./bootstrap && \
    ./configure --prefix=/tmp/imgcat/SampleICC --disable-shared --enable-static && \
    make install

When configuring this repo:

cd /tmp/imgcat
PKG_CONFIG_PATH=./SampleICC/lib/pkgconfig ./configure && make