README.md

libfastimagehash

WIP: Not ready for production use!

libfastimagehash is a imagehash replacement for C/C++.

See also:

• go bindings (with cgo).
• imagehash-web (Javascript version)

*See all benchmarks

Example usage

#include <fastimagehash.h>

int main() {
    unsigned char result[HASH_SIZE];

    phash_file("image.jpeg", result, HASH_SIZE, HIGHFREQ_FACTOR);
}

Build from source

# Download dependencies
apt install libopencv-dev libfftw3-dev cmake

# Checkout source
git clone --recursive https://github.com/simon987/fastimagehash

# Build
cmake .
make

# Install as a system library
sudo make install

Built with

• opencv for image decoding & resizing
• wavelib for wavelet decomposition in whash (With additional CFLAGS)
• fftw3 for DCT in phash
• google/benchmark to measure performance

Disclaimer: The methods used to compute the image hashes are identical to the imagehash python library, however, due to some slight differences in the way OpenCV vs Pillow images are resized, the final image hashes are not always exactly the same.