Redis-ImageScout

A Redis module for indexing images. The module accepts precomputed perceptual hashes of images and indexes them for fast efficient retrieval. A perceptual hash is a fingerprint robust to small distortions - such as compression blurr, scaling, etc. Useful for such things as duplicate detection and copyright protection of images.

Installation

Build and run a docker image:

docker build --tag imgscout:0.1 .
docker run --detach --publish 6379:6379 --mount src=imgscoutdata,dst=/data --name imgscout imgscout:0.1

The client demo program requires the following dependencies pre-installed:

libpng-dev
libtiff-dev
libjpeg-dev

The demo also requires the following but the build will automatically install it:

libphash
libhiredis

To build and install the module:

cmake .
make
make install

To load/unload the module into Redis:

module load /usr/local/lib/imgscout.so
module unload imgscout
module list

Or put this in the redis.conf configuration:

loadmodule /var/local/lib/imgscout.so

Module Commands

The Redis-Imagescout module introduces the mvptree datatype with the following commands:

imgscout.add key hashvalue title [id]

adds a new image perceptual hash to the queue for later addition. When the new additions reaches a threshold number, the new arrivals are added to the index in a batch. To add right away, immediately follow up with the sync command. Returns the id integer value assigned to this image. The title string is added as a hash field to the key: key. Optionally, an id integer can be appended to the end of the command, but this is not the normal use.

imgscout.sync key

adds all the recently submitted image perceptual hashes to the index. Returns an OK status message.

imgscout.query key target-hash radius

queries for all perceptual hash targets within a given radius. Returns an array of results. Each item in the array is also an array of two items: the title string and the id integer.

imgscout.lookup key id

looks up an integer id. Returns the title string.

imgscout.size key

Returns the number of entries in the index.

imgscout.del key id

deletes the id from the index. Returns OK status.

Client Demo Program

Use the imgscoutclient utility to add or query the image files in a given directory. Run ./imgscoutclient -h for all the options. After adding files, be sure to run ./imgscoutclient --cmd sync --key mykey to add the recent additions to the index structure.