scala-phash

License	APL2
Categories	Scala Languages
GroupId	com.github.poslegm
ArtifactId	scala-phash_2.13
Last Version	1.2.2
Release Date	Jun 10, 2019
Type	jar
Description	scala-phash scala-phash
Project URL	https://github.com/poslegm/scala-phash
Project Organization	com.github.poslegm
Source Code Management	https://github.com/poslegm/scala-phash

Download scala-phash_2.13

Filename	Size
scala-phash_2.13-1.2.2.pom
scala-phash_2.13-1.2.2.jar	44 KB
scala-phash_2.13-1.2.2-sources.jar	8 KB
scala-phash_2.13-1.2.2-javadoc.jar	1 MB

How to add to project

Apache Maven

<!-- https://jarcasting.com/artifacts/com.github.poslegm/scala-phash_2.13/ -->
<dependency>
    <groupId>com.github.poslegm</groupId>
    <artifactId>scala-phash_2.13</artifactId>
    <version>1.2.2</version>
</dependency>

Gradle Groovy

// https://jarcasting.com/artifacts/com.github.poslegm/scala-phash_2.13/
implementation 'com.github.poslegm:scala-phash_2.13:1.2.2'

Gradle Kotlin

// https://jarcasting.com/artifacts/com.github.poslegm/scala-phash_2.13/
implementation ("com.github.poslegm:scala-phash_2.13:1.2.2")

Apache Buildr

'com.github.poslegm:scala-phash_2.13:jar:1.2.2'

Apache Ivy

<dependency org="com.github.poslegm" name="scala-phash_2.13" rev="1.2.2">
  <artifact name="scala-phash_2.13" type="jar" />
</dependency>

Groovy Grape

@Grapes(
@Grab(group='com.github.poslegm', module='scala-phash_2.13', version='1.2.2')
)

Scala SBT

libraryDependencies += "com.github.poslegm" % "scala-phash_2.13" % "1.2.2"

Leiningen

[com.github.poslegm/scala-phash_2.13 "1.2.2"]

Dependencies

compile (3)

Group / Artifact	Type	Version
org.scala-lang : scala-library	jar	2.13.0
org.scalactic : scalactic_2.13	jar	3.0.8
com.jhlabs : filters	jar	2.0.235-1

test (1)

Group / Artifact	Type	Version
org.scalatest : scalatest_2.13	jar	3.0.8

Project Modules

There are no modules declared in this project.

Scala pHash

Scala fork of pHash library. This library identifies whether images are similar. You can try it at demo page.

Original pHash uses CImg library for image processing but I could not find CImg for jvm. Therefore I use java.awt and self-made functions for image processing. Consequently, results of my library is different from original phash.

How to use

My library implements three Perceptual Hashing algorithms: Radial Hash, DCT hash and Marr hash. More info about it.

sbt dependencies

libraryDependencies += "com.github.poslegm" %% "scala-phash" % "1.2.2"

API

There is three functions for each hashing algorithm. Let's consider them by example of DCT hash:

• def dctHash(image: BufferedImage): Either[Throwable, DCTHash] ― compute image's hash;
• def unsafeDctHash(image: BufferedImage): DCTHash ― compute image's hash unsafely (danger of exception);
• def dctHashDistance(hash1: DCTHash, hash2: DCTHash): Long ― compare hashes of two images.

Similar functions written for Marr and Radial Hash algorithms.

All public api with scaladocs decsribed in object PHash.

Example

import scalaphash.PHash._
import javax.imageio.ImageIO

val img1 = ImageIO.read(new File("img1.jpg"))
val img2 = ImageIO.read(new File("img2.jpg"))

val radialDistance: Either[Throwable, Double] = for {
  img1rad <- radialHash(img1)
  img2rad <- radialHash(img2)
} yield radialHashDistance(img1rad, img2rad)

radialDistance.foreach {
  case distance if distance > 0.95 => println("similar")
  case _ => println("not similar")
}

radialDistance.left.foreach(e => println(e.getMessage))

Radial distance is more when images are similar. DCT and Marr distances are less when images are similar. Recommended to make a decision on image similarity when at least two hashes pass thresholds.

radial: 0.9508017124330319
dct: 13
marr: 0.5052083333333334

radial: 0.3996241672331173
dct: 41
marr: 0.4704861111111111

Warning

My results is not compatible with original pHash. Use original library if you have an opportunity.
Also, it works much slower than c++ version (about 5-7 times).

Thanks

• pHash / https://github.com/clearscene/pHash
• jphash

Versions

Version
1.2.2 Jun 10, 2019