https://github.com/tonytonyjan/libpuzzle_ruby

This is a C extension for libpuzzle to find similar pictures.
https://github.com/tonytonyjan/libpuzzle_ruby

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This is a C extension for libpuzzle to find similar pictures.

• Host: GitHub
• URL: https://github.com/tonytonyjan/libpuzzle_ruby
• Owner: tonytonyjan
• Created: 2015-06-02T16:02:07.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2016-09-12T17:39:19.000Z (over 8 years ago)
• Last Synced: 2024-10-31T14:19:48.530Z (about 2 months ago)
• Language: Ruby
• Homepage:
• Size: 94.7 KB
• Stars: 8
• Watchers: 4
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
[![Build Status](https://travis-ci.org/tonytonyjan/libpuzzle_ruby.svg?branch=master)](https://travis-ci.org/tonytonyjan/libpuzzle_ruby)

This Ruby gem is made for image simularity comparison, using the C libary [libpuzzle](http://www.pureftpd.org/project/libpuzzle).

# Install

```

gem install libpuzzle

```

Make sure you have installed libpuzzle (>= 0.11) first.

# Install Libpuzzle

Homebrew:

```

brew install libpuzzle

```

APT:

```

apt-get install libpuzzle1 libpuzzle-dev

```

Compile:

```

sudo apt-get install -qq libgd2-xpm-dev

wget http://download.pureftpd.org/pub/pure-ftpd/misc/libpuzzle/releases/libpuzzle-0.11.tar.bz2

tar -xvj -f libpuzzle-0.11.tar.bz2

cd libpuzzle-0.11 && ./configure && make && sudo make install

```

Since the object file is located in `/usr/local/lib`, you might want to export `LD_LIBRARY_PATH` before gem installation, for example:

```

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib

gem install libpuzzle

```

# Usage

```ruby

# load image

p1 = Puzzle.new('foo.png')

p2 = Puzzle.new('bar.png')

p1.similar? p2 # default threshold is 0.6

p1.similar? p2, threshold: 0.7

# get exact distance

p1.distance p2

# compress

p1.compress # => compressed string

# uncompress

Puzzle.uncompress 'COMPRESSED_STRING' # => #

```

# Integrate with ActiveRecord

Follow the naming convention of ActiveRecord, the database schema will look like:

```

+---------------------------------+

|            signatures           |

+---------------------------------+

|   id   | signature | picture_id |

+--------+-----------+------------+

+-------------------------------------+

|                words                |

+-------------------------------------+

| id | position | word | signature_id |

+----+----------+------+--------------+

```

```ruby

class Word < ActiveRecord::Base

  belongs_to :signature

end

class Signature < ActiveRecord::Base

  K, N = 10, 100

  has_many :words

  def cut_vectors_into_words!

    puzzle = Puzzle.uncompress signature

    i = 0

    while i < N && word = puzzle.vector.byteslice(i, K)

      words.find_or_create_by! word: word, position: i

      i += 1

    end

  end

  def similar_signatures

    Signature.distinct.joins(:words)

      .where('EXISTS (SELECT * FROM words AS _words WHERE _words.sig_id = ? AND _words.position = words.position and _words.word = words.word)', id)

      .where.not(id: id)

      .select{ |sig| Puzzle.uncompress(sig.signature) == Puzzle.uncompress(signature) }

  end

end

```