Blockhash

This is Ruby Gem that can be used to produce and compare perceptual image hashes.

This Gem is a translation of the algorithm at http://blockhash.io

Installation

Prerequisites

On Debian/Ubuntu/Mint you can run:

sudo apt get install libmagickwand-dev

On Arch you can run:

pacman -Syy pkg-config imagemagick

On macOS, you can run:

brew install pkg-config imagemagick

Gem Install

Install via Bundler

bundle add blockhash

Or install via RubyGems:

gem install blockhash

Usage

require "blockhash"
require "rmagick"

image1 = Magick::Image.read("image1.png").first
image2 = Magick::Image.read("image2.png").first

# Generate full image hashes
hash1 = Blockhash.calculate(image1, bits = 16)
hash2 = Blockhash.calculate(image2, bits = 16)

# Generate fast image hashes
hash1 = Blockhash.calculate_fast(image1, bits = 16)
hash2 = Blockhash.calculate_fast(image2, bits = 16)

# Generate image hash from file path
hash1 = Blockhash.calculate_from_path("image1.png", bits = 16)

# Determine if hashes are similar
similar = Blockhash.similar?(hash1, hash2, threshold = 10)

# Calculate distance between two hashes
distance = Blockhash.distance(hash1, hash2)

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/actuallydamo/blockhash-ruby.