https://github.com/kseo/blockhash

Haskell implementation of Blockhash perceptual image hash algorithm
https://github.com/kseo/blockhash

Last synced: 27 days ago
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Haskell implementation of Blockhash perceptual image hash algorithm

• Host: GitHub
• URL: https://github.com/kseo/blockhash
• Owner: kseo
• License: bsd-3-clause
• Created: 2016-07-16T16:20:03.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2016-08-30T12:31:16.000Z (about 8 years ago)
• Last Synced: 2024-09-25T06:53:01.667Z (about 1 month ago)
• Language: Haskell
• Homepage: https://hackage.haskell.org/package/blockhash
• Size: 5.33 MB
• Stars: 7
• Watchers: 2
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
blockhash [![Hackage](https://img.shields.io/hackage/v/blockhash.svg?style=flat)](https://hackage.haskell.org/package/blockhash) [![Build Status](https://travis-ci.org/kseo/blockhash.svg?branch=master)](https://travis-ci.org/kseo/blockhash)

=========

This is a perceptual image hash calculation tool based on algorithm described in

Block Mean Value Based Image Perceptual Hashing by Bian Yang, Fan Gu and Xiamu Niu.

Visit [the website][blockhash] for further information.

[blockhash]: http://blockhash.io/

## Program

```

Usage: blockhash [-q|--quick] [-b|--bits ARG] filenames

  blockhash

Available options:

  -h,--help                Show this help text

  -q,--quick               Use quick hashing method

  -b,--bits ARG            Create hash of size N^2 bits.

```

## Library

The example code below uses [JuicyPixels][JuicyPixels] to load images and prints

the hash to stdout.

```haskell

import qualified Codec.Picture as P

import Data.Blockhash

import qualified Data.Vector.Generic as VG

import qualified Data.Vector.Unboxed as V

printHash :: FilePath -> IO ()

printHash filename = do

  res <- P.readImage filename

  case res of

    Left err -> putStrLn ("Fail to read: " ++ filename)

    Right dynamicImage -> do

      let rgbaImage = P.convertRGBA8 dynamicImage

          pixels = VG.convert (P.imageData rgbaImage)

          image = Image { imagePixels = pixels

                        , imageWidth = P.imageWidth rgbaImage

                        , imageHeight = P.imageHeight rgbaImage }

          hash = blockhash image 16 Precise

      putStrLn (show hash)

```

[JuicyPixels]: https://hackage.haskell.org/package/JuicyPixels-3.2.7.2