mirror of https://github.com/perkeep/perkeep.git
501 lines
14 KiB
Go
501 lines
14 KiB
Go
/*
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Copyright 2013 The Perkeep Authors
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package resize
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import (
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"flag"
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"fmt"
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"image"
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"image/color"
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"image/draw"
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"image/png"
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"io"
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"math"
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"os"
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"os/exec"
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"path/filepath"
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"strings"
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"testing"
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)
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const (
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// psnrThreshold is the threshold over which images must match to consider
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// HalveInplace equivalent to Resize. It is in terms of dB and 60-80 is
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// good for RGB.
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psnrThreshold = 50.0
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// TODO(wathiede, mpl): figure out why we got an increase from ~3% to ~16% for
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// YCbCr images in Go 1.5. That is, for halving vs resizing.
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maxPixelDiffPercentage = 10
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)
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var (
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flagOutput = flag.String("output", "", "If non-empty, the directory to save comparison images.")
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flagUseIM = flag.Bool("imagemagick", false, "Use ImageMagick's compare as well to compute the PSNR and create the diff (for some tests)")
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orig = image.Rect(0, 0, 1024, 1024)
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thumb = image.Rect(0, 0, 64, 64)
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)
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var somePalette = []color.Color{
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color.RGBA{0x00, 0x00, 0x00, 0xff},
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color.RGBA{0x00, 0x00, 0x44, 0xff},
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color.RGBA{0x00, 0x00, 0x88, 0xff},
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color.RGBA{0x00, 0x00, 0xcc, 0xff},
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color.RGBA{0x00, 0x44, 0x00, 0xff},
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color.RGBA{0x00, 0x44, 0x44, 0xff},
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color.RGBA{0x00, 0x44, 0x88, 0xff},
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color.RGBA{0x00, 0x44, 0xcc, 0xff},
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}
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func makeImages(r image.Rectangle) []image.Image {
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return []image.Image{
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image.NewGray(r),
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image.NewGray16(r),
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image.NewNRGBA(r),
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image.NewNRGBA64(r),
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image.NewPaletted(r, somePalette),
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image.NewRGBA(r),
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image.NewRGBA64(r),
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image.NewYCbCr(r, image.YCbCrSubsampleRatio444),
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image.NewYCbCr(r, image.YCbCrSubsampleRatio422),
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image.NewYCbCr(r, image.YCbCrSubsampleRatio420),
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image.NewYCbCr(r, image.YCbCrSubsampleRatio440),
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image.NewYCbCr(r, image.YCbCrSubsampleRatio410),
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image.NewYCbCr(r, image.YCbCrSubsampleRatio411),
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}
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}
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func TestResize(t *testing.T) {
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for i, im := range makeImages(orig) {
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m := Resize(im, orig, thumb.Dx(), thumb.Dy())
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got, want := m.Bounds(), thumb
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if !got.Eq(want) {
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t.Error(i, "Want bounds", want, "got", got)
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}
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}
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}
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func TestResampleInplace(t *testing.T) {
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for i, im := range makeImages(orig) {
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m := ResampleInplace(im, orig, thumb.Dx(), thumb.Dy())
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got, want := m.Bounds(), thumb
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if !got.Eq(want) {
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t.Error(i, "Want bounds", want, "got", got)
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}
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}
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}
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func TestResample(t *testing.T) {
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for i, im := range makeImages(orig) {
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m := Resample(im, orig, thumb.Dx(), thumb.Dy())
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got, want := m.Bounds(), thumb
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if !got.Eq(want) {
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t.Error(i, "Want bounds", want, "got", got)
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}
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}
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for _, d := range []struct {
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wantFn string
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r image.Rectangle
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w, h int
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}{
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{
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// Generated with imagemagick:
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// $ convert -crop 128x128+320+160 -resize 64x64 -filter point \
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// testdata/test.png testdata/test-resample-128x128-64x64.png
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wantFn: "test-resample-128x128-64x64.png",
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r: image.Rect(320, 160, 320+128, 160+128),
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w: 64,
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h: 64,
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},
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{
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// Generated with imagemagick:
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// $ convert -resize 128x128 -filter point testdata/test.png \
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// testdata/test-resample-768x576-128x96.png
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wantFn: "test-resample-768x576-128x96.png",
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r: image.Rect(0, 0, 768, 576),
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w: 128,
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h: 96,
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},
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} {
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m := image.NewRGBA(testIm.Bounds())
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fillTestImage(m)
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r, err := os.Open(filepath.Join("testdata", d.wantFn))
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if err != nil {
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t.Fatal(err)
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}
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defer r.Close()
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want, err := png.Decode(r)
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if err != nil {
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t.Fatal(err)
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}
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got := Resample(m, d.r, d.w, d.h)
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res := compareImages(got, want, false)
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t.Logf("PSNR %.4f", res.psnr)
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s := got.Bounds().Size()
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tot := s.X * s.Y
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per := float32(100*res.diffCnt) / float32(tot)
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t.Logf("Resample not the same %d pixels different %.2f%%", res.diffCnt, per)
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if *flagOutput != "" {
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err = savePng(t, want, fmt.Sprintf("Resample.%s->%dx%d.want.png",
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d.r, d.w, d.h))
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if err != nil {
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t.Fatal(err)
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}
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err = savePng(t, got, fmt.Sprintf("Resample.%s->%dx%d.got.png",
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d.r, d.w, d.h))
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if err != nil {
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t.Fatal(err)
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}
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err = savePng(t, res.diffIm,
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fmt.Sprintf("Resample.%s->%dx%d.diff.png", d.r, d.w, d.h))
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if err != nil {
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t.Fatal(err)
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}
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}
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}
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}
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func TestHalveInplace(t *testing.T) {
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for i, im := range makeImages(orig) {
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m := HalveInplace(im)
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b := im.Bounds()
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got, want := m.Bounds(), image.Rectangle{
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Min: b.Min,
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Max: b.Min.Add(b.Max.Div(2)),
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}
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if !got.Eq(want) {
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t.Error(i, "Want bounds", want, "got", got)
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}
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}
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}
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type results struct {
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diffCnt int
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psnr float64
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diffIm *image.Gray
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}
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// if halfSize, m1 has to be 2*m2
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func compareImages(m1, m2 image.Image, halfSize bool) results {
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b := m2.Bounds()
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s := b.Size()
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res := results{}
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mse := uint32(0)
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for y := b.Min.Y; y < b.Max.Y; y++ {
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for x := b.Min.X; x < b.Max.X; x++ {
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var r1, g1, b1, a1 uint32
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if halfSize {
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r1, g1, b1, a1 = m1.At(x*2, y*2).RGBA()
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} else {
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r1, g1, b1, a1 = m1.At(x, y).RGBA()
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}
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r2, g2, b2, a2 := m2.At(x, y).RGBA()
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mse += ((r1-r2)*(r1-r2) + (g1-g2)*(g1-g2) + (b1-b2)*(b1-b2)) / 3
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if r1 != r2 || g1 != g2 || b1 != b2 || a1 != a2 {
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if res.diffIm == nil {
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res.diffIm = image.NewGray(m1.Bounds())
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}
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res.diffCnt++
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res.diffIm.Set(x, y, color.White)
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}
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}
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}
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mse = mse / uint32(s.X*s.Y)
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res.psnr = 20*math.Log10(1<<16) - 10*math.Log10(float64(mse))
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return res
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}
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var testIm image.Image
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func init() {
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r, err := os.Open(filepath.Join("testdata", "test.png"))
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if err != nil {
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panic(err)
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}
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defer r.Close()
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testIm, err = png.Decode(r)
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}
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func fillTestImage(im image.Image) {
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b := im.Bounds()
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if !b.Eq(testIm.Bounds()) {
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panic("Requested target image dimensions not equal reference image.")
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}
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src := testIm
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if dst, ok := im.(*image.YCbCr); ok {
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b := testIm.Bounds()
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for y := b.Min.Y; y < b.Max.Y; y++ {
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for x := b.Min.X; x < b.Max.X; x++ {
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r, g, b, _ := src.At(x, y).RGBA()
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yp, cb, cr := color.RGBToYCbCr(uint8(r), uint8(g), uint8(b))
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dst.Y[dst.YOffset(x, y)] = yp
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off := dst.COffset(x, y)
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dst.Cb[off] = cb
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dst.Cr[off] = cr
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}
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}
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return
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}
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draw.Draw(im.(draw.Image), b, testIm, b.Min, draw.Src)
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}
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func savePng(t *testing.T, m image.Image, fn string) error {
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fn = filepath.Join(*flagOutput, fn)
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t.Log("Saving", fn)
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f, err := os.Create(fn)
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if err != nil {
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return err
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}
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defer f.Close()
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return png.Encode(f, m)
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}
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func getFilename(imType string, method string) string {
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return fmt.Sprintf("%s.%s.png", imType, method)
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}
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func TestCompareResizeToHalveInplace(t *testing.T) {
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t.Skip("Skipping TestCompareResizeToHalveInplace until we know better why resizing YCbCr leads to so many differences.")
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// Here is what I found out so far, while investigating https://github.com/perkeep/perkeep/issues/635:
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// 1) Using imagemagick to compute the PSNR yields (significantly) different results (from
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// the manually computed one in compareImages) for YCbCr images. It is even worse with
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// imagemagick most of the time. It would be interesting to know why.
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// 2) When the diff is generated with imagemagick, we see the difference for each channel,
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// not just in absolute. And it seems that the main distortion is in the red, beats me.
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// 3) TestCompareOriginalToHalveInPlace vs TestCompareOriginalToResized seems to indicate
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// that we're getting more difference (as far as pixel count goes, not in PSNR) when resizing
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// than when halving in place, which is troubling. Furthermore, the diffs generated by
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// TestCompareResizeToHalveInplace looks more similar to TestCompareOriginalToResized than
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// TestCompareOriginalToHalveInPlace, so it looks to me like resizing is the main contributor
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// to the difference we see between resizing and halving.
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// 4) Nevertheless, since both TestCompareOriginalToResized and
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// TestCompareOriginalToHalveInPlace both still (barely) pass, I think it's ok to disable
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// TestCompareResizeToHalveInplace until we know more.
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// 5) If it turns out in the end that there was nothing to worry about, then maybe we could
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// have this test pass, not by lowering the maxPixelDiffPercentage, but by introducing a
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// tolerance such as http://www.imagemagick.org/script/command-line-options.php#fuzz when
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// comparing the pixels.
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if testing.Short() {
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t.Skip("Skipping TestCompareNewResizeToHalveInplace in short mode.")
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}
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testCompareResizeMethods(t, "resize", "halveInPlace")
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}
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func TestCompareOriginalToHalveInPlace(t *testing.T) {
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if testing.Short() {
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t.Skip("Skipping TestCompareOriginalToHalveInPlace in short mode.")
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}
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testCompareWithResized(t, "halveInPlace")
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}
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func TestCompareOriginalToResized(t *testing.T) {
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if testing.Short() {
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t.Skip("Skipping TestCompareOriginalToResized in short mode.")
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}
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testCompareWithResized(t, "resize")
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}
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var resizeMethods = map[string]func(image.Image) image.Image{
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"resize": func(im image.Image) image.Image {
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s := im.Bounds().Size()
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return Resize(im, im.Bounds(), s.X/2, s.Y/2)
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},
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"halveInPlace": func(im image.Image) image.Image {
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return HalveInplace(im)
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},
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}
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func testCompareResizeMethods(t *testing.T, method1, method2 string) {
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images1, images2 := []image.Image{}, []image.Image{}
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var imTypes []string
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for _, im := range makeImages(testIm.Bounds()) {
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// keeping track of the types for the final output
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imgType := fmt.Sprintf("%T", im)
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imgType = imgType[strings.Index(imgType, ".")+1:]
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if m, ok := im.(*image.YCbCr); ok {
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imgType += "." + m.SubsampleRatio.String()
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}
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imTypes = append(imTypes, imgType)
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fillTestImage(im)
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images1 = append(images1, resizeMethods[method1](im))
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}
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for _, im := range makeImages(testIm.Bounds()) {
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fillTestImage(im)
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images2 = append(images2, resizeMethods[method2](im))
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}
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var (
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f io.WriteCloser
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err error
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)
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if *flagOutput != "" {
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os.Mkdir(*flagOutput, os.FileMode(0777))
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f, err = os.Create(filepath.Join(*flagOutput, "index.html"))
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if err != nil {
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t.Fatal(err)
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}
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defer f.Close()
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fmt.Fprintf(f, `<!DOCTYPE html>
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<html lang="en">
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<head>
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<meta charset="utf-8">
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<title>Image comparison for `+method1+` vs `+method2+`</title>
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</head>
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<body style="background-color: grey">
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<table>
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`)
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}
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for i, im1 := range images1 {
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im2 := images2[i]
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res := compareImages(im1, im2, false)
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if *flagOutput != "" {
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fmt.Fprintf(f, "<tr>")
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fn := getFilename(imTypes[i], method1)
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halved := fn
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err := savePng(t, im1, fn)
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if err != nil {
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t.Fatal(err)
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}
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fmt.Fprintf(f, `<td><img src="%s"><br>%s`, fn, fn)
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fn = getFilename(imTypes[i], method2)
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resized := fn
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err = savePng(t, im2, fn)
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if err != nil {
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t.Fatal(err)
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}
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fmt.Fprintf(f, `<td><img src="%s"><br>%s`, fn, fn)
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if res.diffIm != nil {
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fn = getFilename(imTypes[i], "diff")
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err = savePng(t, res.diffIm, fn)
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if err != nil {
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t.Fatal(err)
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}
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fmt.Fprintf(f, `<td><img src="%s"><br>%s`, fn, fn)
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if *flagUseIM {
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cmd := exec.Command("compare", "-verbose", "-metric", "psnr",
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filepath.Join(*flagOutput, halved), filepath.Join(*flagOutput, resized), filepath.Join(*flagOutput, "imagemagick-"+fn))
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if output, err := cmd.CombinedOutput(); err != nil {
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t.Fatalf("%v: %v", string(output), err)
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} else {
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t.Logf("%v", string(output))
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}
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}
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}
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fmt.Fprintln(f)
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}
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if res.psnr < psnrThreshold {
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t.Errorf("%v PSNR too low %.4f", imTypes[i], res.psnr)
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} else {
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t.Logf("%v PSNR %.4f", imTypes[i], res.psnr)
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}
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s := im1.Bounds().Size()
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tot := s.X * s.Y
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if per := float32(100*res.diffCnt) / float32(tot); per > maxPixelDiffPercentage {
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t.Errorf("%v not the same %d pixels different %.2f%%", imTypes[i], res.diffCnt, per)
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}
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}
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}
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// TODO(mpl): refactor with testCompareResizeMethods later
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func testCompareWithResized(t *testing.T, resizeMethod string) {
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images1, images2 := []image.Image{}, []image.Image{}
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var imTypes []string
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for _, im := range makeImages(testIm.Bounds()) {
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// keeping track of the types for the final output
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imgType := fmt.Sprintf("%T", im)
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imgType = imgType[strings.Index(imgType, ".")+1:]
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if m, ok := im.(*image.YCbCr); ok {
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imgType += "." + m.SubsampleRatio.String()
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}
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imTypes = append(imTypes, imgType)
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fillTestImage(im)
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images1 = append(images1, im)
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}
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for _, im := range makeImages(testIm.Bounds()) {
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fillTestImage(im)
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images2 = append(images2, resizeMethods[resizeMethod](im))
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}
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var (
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f io.WriteCloser
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err error
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)
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if *flagOutput != "" {
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os.Mkdir(*flagOutput, os.FileMode(0777))
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f, err = os.Create(filepath.Join(*flagOutput, "index.html"))
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if err != nil {
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t.Fatal(err)
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}
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defer f.Close()
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fmt.Fprintf(f, `<!DOCTYPE html>
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<html lang="en">
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<head>
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<meta charset="utf-8">
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<title>Image comparison for original image vs image resized with `+resizeMethod+`</title>
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</head>
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<body style="background-color: grey">
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<table>
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`)
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}
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for i, im1 := range images1 {
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im2 := images2[i]
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res := compareImages(im1, im2, true)
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if *flagOutput != "" {
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fmt.Fprintf(f, "<tr>")
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fn := getFilename(imTypes[i], "ori")
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err := savePng(t, im1, fn)
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if err != nil {
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t.Fatal(err)
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}
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fmt.Fprintf(f, `<td><img src="%s"><br>%s`, fn, fn)
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fn = getFilename(imTypes[i], resizeMethod)
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|
err = savePng(t, im2, fn)
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
fmt.Fprintf(f, `<td><img src="%s"><br>%s`, fn, fn)
|
|
|
|
if res.diffIm != nil {
|
|
fn = getFilename(imTypes[i], "diff")
|
|
err = savePng(t, res.diffIm, fn)
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
fmt.Fprintf(f, `<td><img src="%s"><br>%s`, fn, fn)
|
|
}
|
|
fmt.Fprintln(f)
|
|
}
|
|
|
|
if res.psnr < psnrThreshold {
|
|
t.Errorf("%v PSNR too low %.4f", imTypes[i], res.psnr)
|
|
} else {
|
|
t.Logf("%v PSNR %.4f", imTypes[i], res.psnr)
|
|
}
|
|
s := im1.Bounds().Size()
|
|
tot := s.X * s.Y
|
|
if per := float32(100*res.diffCnt) / float32(tot); per > maxPixelDiffPercentage {
|
|
t.Errorf("%v not the same %d pixels different %.2f%%", imTypes[i], res.diffCnt, per)
|
|
}
|
|
}
|
|
}
|