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package resize
import (
"image"
"image/color"
"runtime"
"testing"
)
var img = image.NewGray16(image.Rect(0, 0, 3, 3))
func init() {
runtime.GOMAXPROCS(runtime.NumCPU())
img.Set(1, 1, color.White)
}
func Test_Param1(t *testing.T) {
m := Resize(0, 0, img, NearestNeighbor)
if m.Bounds() != img.Bounds() {
t.Fail()
}
}
func Test_Param2(t *testing.T) {
m := Resize(100, 0, img, NearestNeighbor)
if m.Bounds() != image.Rect(0, 0, 100, 100) {
t.Fail()
}
}
func Test_ZeroImg(t *testing.T) {
zeroImg := image.NewGray16(image.Rect(0, 0, 0, 0))
m := Resize(0, 0, zeroImg, NearestNeighbor)
if m.Bounds() != zeroImg.Bounds() {
t.Fail()
}
}
func Test_CorrectResize(t *testing.T) {
zeroImg := image.NewGray16(image.Rect(0, 0, 256, 256))
m := Resize(60, 0, zeroImg, NearestNeighbor)
if m.Bounds() != image.Rect(0, 0, 60, 60) {
t.Fail()
}
}
func Test_SameColor(t *testing.T) {
img := image.NewRGBA(image.Rect(0, 0, 20, 20))
for y := img.Bounds().Min.Y; y < img.Bounds().Max.Y; y++ {
for x := img.Bounds().Min.X; x < img.Bounds().Max.X; x++ {
img.SetRGBA(x, y, color.RGBA{0x80, 0x80, 0x80, 0xFF})
}
}
out := Resize(10, 10, img, Lanczos3)
for y := out.Bounds().Min.Y; y < out.Bounds().Max.Y; y++ {
for x := out.Bounds().Min.X; x < out.Bounds().Max.X; x++ {
color := img.At(x, y).(color.RGBA)
if color.R != 0x80 || color.G != 0x80 || color.B != 0x80 || color.A != 0xFF {
t.Fail()
}
}
}
}
func Test_Bounds(t *testing.T) {
img := image.NewRGBA(image.Rect(20, 10, 200, 99))
out := Resize(80, 80, img, Lanczos2)
out.At(0, 0)
}
func Test_SameSizeReturnsOriginal(t *testing.T) {
img := image.NewRGBA(image.Rect(0, 0, 10, 10))
out := Resize(0, 0, img, Lanczos2)
if img != out {
t.Fail()
}
out = Resize(10, 10, img, Lanczos2)
if img != out {
t.Fail()
}
}
func Test_PixelCoordinates(t *testing.T) {
checkers := image.NewGray(image.Rect(0, 0, 4, 4))
checkers.Pix = []uint8{
255, 0, 255, 0,
0, 255, 0, 255,
255, 0, 255, 0,
0, 255, 0, 255,
}
resized := Resize(12, 12, checkers, NearestNeighbor).(*image.Gray)
if resized.Pix[0] != 255 || resized.Pix[1] != 255 || resized.Pix[2] != 255 {
t.Fail()
}
if resized.Pix[3] != 0 || resized.Pix[4] != 0 || resized.Pix[5] != 0 {
t.Fail()
}
}
func Test_ResizeWithPremultipliedAlpha(t *testing.T) {
img := image.NewRGBA(image.Rect(0, 0, 1, 4))
for y := img.Bounds().Min.Y; y < img.Bounds().Max.Y; y++ {
// 0x80 = 0.5 * 0xFF.
img.SetRGBA(0, y, color.RGBA{0x80, 0x80, 0x80, 0x80})
}
out := Resize(1, 2, img, MitchellNetravali)
outputColor := out.At(0, 0).(color.NRGBA)
if outputColor.R != 0xFF {
t.Fail()
}
}
const (
// Use a small image size for benchmarks. We don't want memory performance
// to affect the benchmark results.
benchMaxX = 250
benchMaxY = 250
// Resize values near the original size require increase the amount of time
// resize spends converting the image.
benchWidth = 200
benchHeight = 200
)
func benchRGBA(b *testing.B, interp InterpolationFunction) {
m := image.NewRGBA(image.Rect(0, 0, benchMaxX, benchMaxY))
// Initialize m's pixels to create a non-uniform image.
for y := m.Rect.Min.Y; y < m.Rect.Max.Y; y++ {
for x := m.Rect.Min.X; x < m.Rect.Max.X; x++ {
i := m.PixOffset(x, y)
m.Pix[i+0] = uint8(y + 4*x)
m.Pix[i+1] = uint8(y + 4*x)
m.Pix[i+2] = uint8(y + 4*x)
m.Pix[i+3] = uint8(4*y + x)
}
}
var out image.Image
b.ResetTimer()
for i := 0; i < b.N; i++ {
out = Resize(benchWidth, benchHeight, m, interp)
}
out.At(0, 0)
}
// The names of some interpolation functions are truncated so that the columns
// of 'go test -bench' line up.
func Benchmark_Nearest_RGBA(b *testing.B) {
benchRGBA(b, NearestNeighbor)
}
func Benchmark_Bilinear_RGBA(b *testing.B) {
benchRGBA(b, Bilinear)
}
func Benchmark_Bicubic_RGBA(b *testing.B) {
benchRGBA(b, Bicubic)
}
func Benchmark_Mitchell_RGBA(b *testing.B) {
benchRGBA(b, MitchellNetravali)
}
func Benchmark_Lanczos2_RGBA(b *testing.B) {
benchRGBA(b, Lanczos2)
}
func Benchmark_Lanczos3_RGBA(b *testing.B) {
benchRGBA(b, Lanczos3)
}
func benchYCbCr(b *testing.B, interp InterpolationFunction) {
m := image.NewYCbCr(image.Rect(0, 0, benchMaxX, benchMaxY), image.YCbCrSubsampleRatio422)
// Initialize m's pixels to create a non-uniform image.
for y := m.Rect.Min.Y; y < m.Rect.Max.Y; y++ {
for x := m.Rect.Min.X; x < m.Rect.Max.X; x++ {
yi := m.YOffset(x, y)
ci := m.COffset(x, y)
m.Y[yi] = uint8(16*y + x)
m.Cb[ci] = uint8(y + 16*x)
m.Cr[ci] = uint8(y + 16*x)
}
}
var out image.Image
b.ResetTimer()
for i := 0; i < b.N; i++ {
out = Resize(benchWidth, benchHeight, m, interp)
}
out.At(0, 0)
}
func Benchmark_Nearest_YCC(b *testing.B) {
benchYCbCr(b, NearestNeighbor)
}
func Benchmark_Bilinear_YCC(b *testing.B) {
benchYCbCr(b, Bilinear)
}
func Benchmark_Bicubic_YCC(b *testing.B) {
benchYCbCr(b, Bicubic)
}
func Benchmark_Mitchell_YCC(b *testing.B) {
benchYCbCr(b, MitchellNetravali)
}
func Benchmark_Lanczos2_YCC(b *testing.B) {
benchYCbCr(b, Lanczos2)
}
func Benchmark_Lanczos3_YCC(b *testing.B) {
benchYCbCr(b, Lanczos3)
}
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