DSSIM comparison for chroma lossiness PR to FLIF

compare.scala

import scala.sys.process._
import java.nio.file.Files
import java.nio.file.Paths

val flif1 = args(0)
val flif2 = args(1)

val imgBase = args(2)

val images = Seq("ls", "-1", imgBase).lineStream.filter(_.endsWith(".png")).toList

def fileSize(p: String) = Files.size(Paths.get(p))

def dssim(i1: String, i2: String) = {
  val out = Seq("dssim", i1, i2).!!
  out.split("\t")(0).toFloat
}

images.foreach { img =>
  for (q <- 0 until 100 by 20) {
    val fullImgPath = imgBase + "/"+ img
    val img1 = s"out/$img-1-$q.flif"
    val img2 = s"out/$img-2-$q.flif"
    val img1png = s"out/$img-1-$q.png"
    val img2png = s"out/$img-2-$q.png"

    Seq(flif1, s"-Q$q", fullImgPath, img1).!
    Seq(flif2, s"-Q$q", fullImgPath, img2).!

    Seq(flif1, img1, img1png).!
    Seq(flif2, img2, img2png).!

    val dssim1 = dssim(fullImgPath, img1png)
    val dssim2 = dssim(fullImgPath, img2png)
    println(Seq(img, q, fileSize(fullImgPath), fileSize(img1), fileSize(img2), dssim1, dssim2, f"${(dssim2 - dssim1)}%.5f").mkString(", "))
  }
}

results.csv