kylerwinters / scala-phash

Image comparison by hash codes

Scala pHash

Scala fork of pHash library. This library identifies whether images are similar.
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" % "1.0.1"

Example

import com.github.poslegm.scalaphash.PHash
import javax.imageio.ImageIO

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

val img1rad = PHash.radialHash(img1)
val img2rad = PHash.radialHash(img2)

val radialDistance = PHash.radialHashDistance(img1rad, img2rad)

if (radialDistance > 0.95) {
  println("similar")
} else {
  println("not similar")
}

Radial distance is more when images are similar. DCT and Marr distances are less when images are similar.

radial: 0.9538751316650709
dct: 1
marr: 0.3315972222222222

radial: 0.36438994709451805
dct: 36
marr: 0.4947916666666667

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