func main() {
var outFile *os.File
var err error
if outFile, err = os.Create("create.png"); err != nil {
println("Error", err)
return
}
defer outFile.Close()
rect := image.Rect(0, 0, 100, 100)
rgba := image.NewRGBA64(rect)
// #golangとか書きたいけど、とりあえず#だけ
for i := 0; i < 10; i++ {
rgba.Set(60, (10 + i), image.Black.At(0, 0))
rgba.Set(65, (10 + i), image.Black.At(0, 0))
rgba.Set((58 + i), 13, image.Black.At(0, 0))
rgba.Set((58 + i), 16, image.Black.At(0, 0))
}
outImage := rgba.SubImage(rect)
if err = png.Encode(outFile, outImage); err != nil {
println("Error", err)
return
}
}
// Resize an image to new width and height using the interpolation function interp.
// A new image with the given dimensions will be returned.
// If one of the parameters width or height is set to 0, its size will be calculated so that
// the aspect ratio is that of the originating image.
// The resizing algorithm uses channels for parallel computation.
func Resize(width, height uint, img image.Image, interp InterpolationFunction) image.Image {
oldBounds := img.Bounds()
oldWidth := float32(oldBounds.Dx())
oldHeight := float32(oldBounds.Dy())
scaleX, scaleY := calcFactors(width, height, oldWidth, oldHeight)
tempImg := image.NewRGBA64(image.Rect(0, 0, oldBounds.Dy(), int(0.7+oldWidth/scaleX)))
b := tempImg.Bounds()
adjust := 0.5 * ((oldWidth-1.0)/scaleX - float32(b.Dy()-1))
n := numJobs(b.Dy())
c := make(chan int, n)
for i := 0; i < n; i++ {
slice := image.Rect(b.Min.X, b.Min.Y+i*(b.Dy())/n, b.Max.X, b.Min.Y+(i+1)*(b.Dy())/n)
go resizeSlice(img, tempImg, interp, scaleX, adjust, float32(oldBounds.Min.X), slice, c)
}
for i := 0; i < n; i++ {
<-c
}
resultImg := image.NewRGBA64(image.Rect(0, 0, int(0.7+oldWidth/scaleX), int(0.7+oldHeight/scaleY)))
b = resultImg.Bounds()
adjust = 0.5 * ((oldHeight-1.0)/scaleY - float32(b.Dy()-1))
for i := 0; i < n; i++ {
slice := image.Rect(b.Min.X, b.Min.Y+i*(b.Dy())/n, b.Max.X, b.Min.Y+(i+1)*(b.Dy())/n)
go resizeSlice(tempImg, resultImg, interp, scaleY, adjust, float32(oldBounds.Min.Y), slice, c)
}
for i := 0; i < n; i++ {
<-c
}
return resultImg
}
func NewImageOfTypeRect(src image.Image, bounds image.Rectangle) image.Image {
switch i := src.(type) {
case *image.Alpha:
return image.NewAlpha(bounds)
case *image.Alpha16:
return image.NewAlpha16(bounds)
case *image.Gray:
return image.NewGray(bounds)
case *image.Gray16:
return image.NewGray16(bounds)
case *image.NRGBA:
return image.NewNRGBA(bounds)
case *image.NRGBA64:
return image.NewNRGBA64(bounds)
case *image.Paletted:
return image.NewPaletted(bounds, i.Palette)
case *image.RGBA:
return image.NewRGBA(bounds)
case *image.RGBA64:
return image.NewRGBA64(bounds)
case *image.YCbCr:
return image.NewYCbCr(bounds, i.SubsampleRatio)
}
panic("Unknown image type")
}
func orient(r io.Reader, i image.Image) (image.Image, error) {
t := log.Start()
defer log.End(t)
e, err := exif.Decode(r)
if err != nil {
log.Printf("fail to decode exif: %v", err)
return nil, err
}
tag, err := e.Get(exif.Orientation)
// Orientationタグが存在しない場合、処理を完了する
if err != nil {
log.Println("oritentation tag doesn't exist")
return nil, err
}
o, err := tag.Int(0)
if err != nil {
log.Println("oritentation tag is't int")
return nil, err
}
rect := i.Bounds()
// orientation=5~8 なら画像サイズの縦横を入れ替える
if o >= 5 && o <= 8 {
rect = RotateRect(rect)
}
d := image.NewRGBA64(rect)
a := affines[o]
a.TransformCenter(d, i, interp.Bilinear)
return d, nil
}
// NewDrawableSize returns a new draw.Image with the same type as p and the given bounds.
// If p is not a draw.Image, another type is used.
func NewDrawableSize(p image.Image, r image.Rectangle) draw.Image {
switch p := p.(type) {
case *image.RGBA:
return image.NewRGBA(r)
case *image.RGBA64:
return image.NewRGBA64(r)
case *image.NRGBA:
return image.NewNRGBA(r)
case *image.NRGBA64:
return image.NewNRGBA64(r)
case *image.Alpha:
return image.NewAlpha(r)
case *image.Alpha16:
return image.NewAlpha16(r)
case *image.Gray:
return image.NewGray(r)
case *image.Gray16:
return image.NewGray16(r)
case *image.Paletted:
pl := make(color.Palette, len(p.Palette))
copy(pl, p.Palette)
return image.NewPaletted(r, pl)
case *image.CMYK:
return image.NewCMYK(r)
default:
return image.NewRGBA(r)
}
}
// Resample returns a resampled copy of the image slice r of m.
// The returned image has width w and height h.
func Resample(m image.Image, r image.Rectangle, w, h int) image.Image {
if w < 0 || h < 0 {
return nil
}
if w == 0 || h == 0 || r.Dx() <= 0 || r.Dy() <= 0 {
return image.NewRGBA64(image.Rect(0, 0, w, h))
}
img := image.NewRGBA(image.Rect(0, 0, w, h))
xStep := float64(r.Dx()) / float64(w)
yStep := float64(r.Dy()) / float64(h)
for y := 0; y < h; y++ {
for x := 0; x < w; x++ {
xSrc := int(float64(r.Min.X) + float64(x)*xStep)
ySrc := int(float64(r.Min.Y) + float64(y)*yStep)
r, g, b, a := m.At(xSrc, ySrc).RGBA()
img.SetRGBA(x, y, color.RGBA{
R: uint8(r >> 8),
G: uint8(g >> 8),
B: uint8(b >> 8),
A: uint8(a >> 8),
})
}
}
return img
}
func Crop(m image.Image, r image.Rectangle, w, h int) image.Image {
if w < 0 || h < 0 {
return nil
}
if w == 0 || h == 0 || r.Dx() <= 0 || r.Dy() <= 0 {
return image.NewRGBA64(image.Rect(0, 0, w, h))
}
curw, curh := r.Min.X, r.Min.Y
img := image.NewRGBA(image.Rect(0, 0, w, h))
for y := 0; y < h; y++ {
for x := 0; x < w; x++ {
// Get a source pixel.
subx := curw + x
suby := curh + y
r32, g32, b32, a32 := m.At(subx, suby).RGBA()
r := uint8(r32 >> 8)
g := uint8(g32 >> 8)
b := uint8(b32 >> 8)
a := uint8(a32 >> 8)
img.SetRGBA(x, y, color.RGBA{r, g, b, a})
}
}
return img
}
func TestIsHighQuality(t *testing.T) {
r := image.Rect(0, 0, 1, 1)
for _, tc := range []struct {
name string
p image.Image
expected bool
}{
{
name: "RGBA64",
p: image.NewRGBA64(r),
expected: true,
},
{
name: "NRGBA64",
p: image.NewNRGBA64(r),
expected: true,
},
{
name: "RGBA",
p: image.NewRGBA(r),
expected: false,
},
} {
t.Run(tc.name, func(t *testing.T) {
res := isHighQuality(tc.p)
if res != tc.expected {
t.Fatalf("unexpected result for %T: got %t, want %t", tc.p, res, tc.expected)
}
})
}
}
func TestIsHighQuality(t *testing.T) {
r := image.Rect(0, 0, 1, 1)
type TC struct {
p image.Image
expected bool
}
for _, tc := range []TC{
{
p: image.NewRGBA64(r),
expected: true,
},
{
p: image.NewNRGBA64(r),
expected: true,
},
{
p: image.NewRGBA(r),
expected: false,
},
} {
res := isHighQuality(tc.p)
if res != tc.expected {
t.Fatalf("unexpected result for %T: got %t, want %t", tc.p, res, tc.expected)
}
}
}
func createRandomImage(maxPaletteSize int) image.Image {
r := image.Rectangle{Min: image.Point{0, 0}, Max: image.Point{gen.Rand(32) + 1, gen.Rand(32) + 1}}
var img Image
switch gen.Rand(10) {
case 0:
img = image.NewAlpha(r)
case 1:
img = image.NewAlpha16(r)
case 2:
img = image.NewCMYK(r)
case 3:
img = image.NewGray(r)
case 4:
img = image.NewGray16(r)
case 5:
img = image.NewNRGBA(r)
case 6:
img = image.NewNRGBA64(r)
case 7:
img = image.NewPaletted(r, randPalette(maxPaletteSize))
case 8:
img = image.NewRGBA(r)
case 9:
img = image.NewRGBA64(r)
default:
panic("bad")
}
fill := gen.Rand(19)
var palette []color.Color
if fill == 17 {
palette = randPalette(maxPaletteSize)
}
for y := 0; y < r.Max.Y; y++ {
for x := 0; x < r.Max.X; x++ {
switch {
case fill <= 15:
img.Set(x, y, color.RGBA64{
^uint16(0) * uint16((fill>>0)&1),
^uint16(0) * uint16((fill>>1)&1),
^uint16(0) * uint16((fill>>2)&1),
^uint16(0) * uint16((fill>>3)&1),
})
case fill == 16:
img.Set(x, y, randColor())
case fill == 17:
img.Set(x, y, palette[gen.Rand(len(palette))])
case fill == 18:
if gen.Rand(3) != 0 {
img.Set(x, y, color.RGBA64{})
} else {
img.Set(x, y, randColor())
}
default:
panic("bad")
}
}
}
return img.(image.Image)
}
func main() {
var cpus *int
if runtime.GOMAXPROCS(0) == 1 {
cpus = flag.Int("cpus", runtime.NumCPU(), "the number of processor cores to use at any given time")
} else {
cpus = flag.Int("cpus", runtime.GOMAXPROCS(0), "the number of processor cores to use at any given time")
}
flag.Parse()
if *cpuprof != "" {
f, err := os.Create(*cpuprof)
if err != nil {
panic(err)
}
defer f.Close()
pprof.StartCPUProfile(f)
defer pprof.StopCPUProfile()
}
runtime.GOMAXPROCS(*cpus)
noise0 = NewNoiseGen(0, *oct)
noise1 = NewNoiseGen(1, *oct)
noise2 = NewNoiseGen(2, *oct)
var wg sync.WaitGroup
dim := *ppi * *ppp
img := image.NewRGBA64(image.Rect(0, 0, dim, dim))
ch := make(chan [2]int, 16)
for i := 0; i < *cpus; i++ {
go Worker(ch, img, &wg)
}
for x := 0; x < dim; x++ {
for y := 0; y < dim; y++ {
wg.Add(1)
ch <- [2]int{x, y}
}
}
close(ch)
wg.Wait()
f, err := os.Create(*output)
if err != nil {
panic(err)
}
defer f.Close()
err = png.Encode(f, img)
if err != nil {
panic(err)
}
}
// ConvertToRGBA64 returns an *image.RGBA64 instance by asserting the given
// ImageReader has that type or, if it does not, using Copy to concurrently
// set the color.Color values of a new *image.RGBA64 instance with the same
// bounds.
func ConvertToRGBA64(src ImageReader) *image.RGBA64 {
if dst, ok := src.(*image.RGBA64); ok {
return dst
}
dst := image.NewRGBA64(src.Bounds())
Copy(dst, src)
return dst
}
func tToRGBA64(m image.Image) *image.RGBA64 {
if p, ok := m.(*image.RGBA64); ok {
return p
}
p := image.NewRGBA64(m.Bounds())
xdraw.Draw(p, p.Bounds(), m, image.Pt(0, 0), xdraw.Src)
return p
}
func BenchmarkEncodeRGBA64(b *testing.B) {
img := image.NewRGBA64(image.Rect(0, 0, 1<<10, 1<<10))
io.ReadFull(rand.Reader, img.Pix)
b.ResetTimer()
for i := 0; i < b.N; i++ {
Encode(ioutil.Discard, img)
}
}
func TestSubImage(t *testing.T) {
testData := []struct {
desc string
img draw.Image
ok bool
}{
{
"sub image (Gray)",
image.NewGray(image.Rect(0, 0, 10, 10)),
true,
},
{
"sub image (Gray16)",
image.NewGray16(image.Rect(0, 0, 10, 10)),
true,
},
{
"sub image (RGBA)",
image.NewRGBA(image.Rect(0, 0, 10, 10)),
true,
},
{
"sub image (RGBA64)",
image.NewRGBA64(image.Rect(0, 0, 10, 10)),
true,
},
{
"sub image (NRGBA)",
image.NewNRGBA(image.Rect(0, 0, 10, 10)),
true,
},
{
"sub image (NRGBA64)",
image.NewNRGBA64(image.Rect(0, 0, 10, 10)),
true,
},
{
"sub image (fake)",
fakeDrawImage{image.Rect(0, 0, 10, 10)},
false,
},
}
for _, d := range testData {
simg, ok := getSubImage(d.img, image.Pt(3, 3))
if ok != d.ok {
t.Errorf("test [%s] failed: expected %#v, got %#v", d.desc, d.ok, ok)
} else if ok {
simg.Set(5, 5, color.NRGBA{255, 255, 255, 255})
r, g, b, a := d.img.At(5, 5).RGBA()
if r != 0xffff || g != 0xffff || b != 0xffff || a != 0xffff {
t.Errorf("test [%s] failed: expected (0xffff, 0xffff, 0xffff, 0xffff), got (%d, %d, %d, %d)", d.desc, r, g, b, a)
}
}
}
}
func TestIsOpaque(t *testing.T) {
type opqt struct {
img image.Image
opaque bool
}
var testData []opqt
testData = append(testData, opqt{image.NewNRGBA(image.Rect(0, 0, 1, 1)), false})
testData = append(testData, opqt{image.NewNRGBA64(image.Rect(0, 0, 1, 1)), false})
testData = append(testData, opqt{image.NewRGBA(image.Rect(0, 0, 1, 1)), false})
testData = append(testData, opqt{image.NewRGBA64(image.Rect(0, 0, 1, 1)), false})
testData = append(testData, opqt{image.NewGray(image.Rect(0, 0, 1, 1)), true})
testData = append(testData, opqt{image.NewGray16(image.Rect(0, 0, 1, 1)), true})
testData = append(testData, opqt{image.NewYCbCr(image.Rect(0, 0, 1, 1), image.YCbCrSubsampleRatio444), true})
testData = append(testData, opqt{image.NewAlpha(image.Rect(0, 0, 1, 1)), false})
img1 := image.NewNRGBA(image.Rect(0, 0, 1, 1))
img1.Set(0, 0, color.NRGBA{0x00, 0x00, 0x00, 0xff})
testData = append(testData, opqt{img1, true})
img2 := image.NewNRGBA64(image.Rect(0, 0, 1, 1))
img2.Set(0, 0, color.NRGBA{0x00, 0x00, 0x00, 0xff})
testData = append(testData, opqt{img2, true})
img3 := image.NewRGBA(image.Rect(0, 0, 1, 1))
img3.Set(0, 0, color.NRGBA{0x00, 0x00, 0x00, 0xff})
testData = append(testData, opqt{img3, true})
img4 := image.NewRGBA64(image.Rect(0, 0, 1, 1))
img4.Set(0, 0, color.NRGBA{0x00, 0x00, 0x00, 0xff})
testData = append(testData, opqt{img4, true})
imgp1 := image.NewPaletted(image.Rect(0, 0, 1, 1), []color.Color{color.NRGBA{0x00, 0x00, 0x00, 0xff}})
imgp1.SetColorIndex(0, 0, 0)
testData = append(testData, opqt{imgp1, true})
imgp2 := image.NewPaletted(image.Rect(0, 0, 1, 1), []color.Color{color.NRGBA{0x00, 0x00, 0x00, 0xfe}})
imgp2.SetColorIndex(0, 0, 0)
testData = append(testData, opqt{imgp2, false})
for _, d := range testData {
isop := isOpaque(d.img)
if isop != d.opaque {
t.Errorf("isOpaque failed %#v, %v", d.img, isop)
}
}
}
func TestEncodeEmptyImage(t *testing.T) {
img := image.NewRGBA64(image.Rect(0, 0, 0, 0))
w := new(bytes.Buffer)
err := Encode(w, img)
if err != nil {
t.Errorf("err is not nil: %v", err)
}
if 0 != bytes.Compare(w.Bytes(), []byte("farbfeld\000\000\000\000\000\000\000\000")) {
t.Errorf("encoded image differs")
}
}
func Rect(src image.Image, r image.Rectangle, at At) image.Image {
dst := image.NewRGBA64(image.Rectangle{image.ZP, r.Size()})
b := dst.Bounds()
for x := r.Min.X; x < r.Max.X; x++ {
for y := r.Min.Y; y < r.Max.Y; y++ {
p := image.Pt(x, y).Sub(r.Min).Add(b.Min)
dst.Set(p.X, p.Y, at(src, image.Pt(x, y)))
}
}
return dst
}
// Add the interface to export image
func ReadPixels(x int, y int, w int, h int) image.Image {
data := make([]uint16, 4*w*h)
p := unsafe.Pointer(&data[0])
C.glReadPixels(C.GLint(x), C.GLint(y), C.GLsizei(w), C.GLsizei(h), C.GLenum(RGBA), C.GLenum(UNSIGNED_SHORT), p)
rec := image.Rect(x, y, x+w, y+h)
rgba := image.NewRGBA64(rec)
for i := 0; i < w*h; i++ {
c := color.RGBA64{data[4*i], data[4*i+1], data[4*i+2], data[4*i+3]}
rgba.Set(i%w, h-i/w-1, c)
}
return rgba
}
// Returns the Image to be used for output operations. If patch is
// true and `out' describes an existing image, we will load and use
// that image; note that if the image is a different size than the
// `src' image we return an error. If patch is true and `out' does
// not describe a valid image, we return an error. Otherwise, we
// return a blank image.
func outputImage(src image.Image, out string, patch bool) (*image.RGBA64, error) {
if patch {
if out == "" {
return nil, errors.New("Cannot patch without an explicit output file")
}
if img, _, err := readImage(out); err != nil {
return nil, err
} else {
src_bounds := src.Bounds()
img_bounds := img.Bounds()
// Check the size of the image
if img_bounds.Size() != src_bounds.Size() {
img_w := img_bounds.Size().X
img_h := img_bounds.Size().Y
src_w := src_bounds.Size().X
src_h := src_bounds.Size().Y
unf_msg := "Output image's size (%d x %d) does not match " +
"the input image's size (%d x %d)"
msg := fmt.Sprintf(unf_msg, img_w, img_h, src_w, src_h)
return nil, errors.New(msg)
}
// We now need to coerce the image into the image.RGBA64
// format. We use src.Bounds() so the coordinate systems are
// consistent.
ret := image.NewRGBA64(src.Bounds())
for x := src_bounds.Min.X; x < src_bounds.Max.X; x++ {
for y := src_bounds.Min.Y; y < src_bounds.Max.Y; y++ {
ret.Set(x, y, img.At(x, y))
}
}
return ret, nil
}
} else {
// We use src.Bounds() so the coordinate systems are consistent.
return image.NewRGBA64(src.Bounds()), nil
}
}
func (this JpegImg) SaveToFile(path string) {
img := image.NewRGBA64(this.bounds)
pos := 0
for y := this.bounds.Min.Y; y < this.bounds.Max.Y; y++ {
for x := this.bounds.Min.X; x < this.bounds.Max.X; x++ {
img.Set(x, y, this.Pixels[pos])
pos++
}
}
outfile, _ := os.Create(path)
defer outfile.Close()
jpeg.Encode(outfile, img, nil)
}
func TestNewPixelGetter(t *testing.T) {
var img image.Image
var pg *pixelGetter
img = image.NewNRGBA(image.Rect(0, 0, 1, 1))
pg = newPixelGetter(img)
if pg.imgType != itNRGBA || pg.imgNRGBA == nil || !img.Bounds().Eq(pg.imgBounds) {
t.Error("newPixelGetter NRGBA")
}
img = image.NewNRGBA64(image.Rect(0, 0, 1, 1))
pg = newPixelGetter(img)
if pg.imgType != itNRGBA64 || pg.imgNRGBA64 == nil || !img.Bounds().Eq(pg.imgBounds) {
t.Error("newPixelGetter NRGBA64")
}
img = image.NewRGBA(image.Rect(0, 0, 1, 1))
pg = newPixelGetter(img)
if pg.imgType != itRGBA || pg.imgRGBA == nil || !img.Bounds().Eq(pg.imgBounds) {
t.Error("newPixelGetter RGBA")
}
img = image.NewRGBA64(image.Rect(0, 0, 1, 1))
pg = newPixelGetter(img)
if pg.imgType != itRGBA64 || pg.imgRGBA64 == nil || !img.Bounds().Eq(pg.imgBounds) {
t.Error("newPixelGetter RGBA64")
}
img = image.NewGray(image.Rect(0, 0, 1, 1))
pg = newPixelGetter(img)
if pg.imgType != itGray || pg.imgGray == nil || !img.Bounds().Eq(pg.imgBounds) {
t.Error("newPixelGetter Gray")
}
img = image.NewGray16(image.Rect(0, 0, 1, 1))
pg = newPixelGetter(img)
if pg.imgType != itGray16 || pg.imgGray16 == nil || !img.Bounds().Eq(pg.imgBounds) {
t.Error("newPixelGetter Gray16")
}
img = image.NewYCbCr(image.Rect(0, 0, 1, 1), image.YCbCrSubsampleRatio422)
pg = newPixelGetter(img)
if pg.imgType != itYCbCr || pg.imgYCbCr == nil || !img.Bounds().Eq(pg.imgBounds) {
t.Error("newPixelGetter YCbCr")
}
img = image.NewUniform(color.NRGBA64{0, 0, 0, 0})
pg = newPixelGetter(img)
if pg.imgType != itGeneric || pg.imgGeneric == nil || !img.Bounds().Eq(pg.imgBounds) {
t.Error("newPixelGetter Generic(Uniform)")
}
img = image.NewAlpha(image.Rect(0, 0, 1, 1))
pg = newPixelGetter(img)
if pg.imgType != itGeneric || pg.imgGeneric == nil || !img.Bounds().Eq(pg.imgBounds) {
t.Error("newPixelGetter Generic(Alpha)")
}
}
func makeImages(r image.Rectangle) []image.Image {
return []image.Image{
image.NewGray(r),
image.NewGray16(r),
image.NewNRGBA(r),
image.NewNRGBA64(r),
image.NewPaletted(r, somePalette),
image.NewRGBA(r),
image.NewRGBA64(r),
image.NewYCbCr(r, image.YCbCrSubsampleRatio444),
image.NewYCbCr(r, image.YCbCrSubsampleRatio422),
image.NewYCbCr(r, image.YCbCrSubsampleRatio420),
image.NewYCbCr(r, image.YCbCrSubsampleRatio440),
}
}
func imgType(im image.Image, w, h int) imageng {
var scaled imageng
switch im.ColorModel() {
case image.RGBAColorModel:
scaled = image.NewRGBA(w, h)
case image.NRGBAColorModel:
scaled = image.NewNRGBA(w, h)
case image.GrayColorModel:
scaled = image.NewGray(w, h)
case image.Gray16ColorModel:
scaled = image.NewGray16(w, h)
default:
scaled = image.NewRGBA64(w, h)
}
return scaled
}
func Test_SameColorWithRGBA64(t *testing.T) {
img := image.NewRGBA64(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.SetRGBA64(x, y, color.RGBA64{0x8000, 0x8000, 0x8000, 0xFFFF})
}
}
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 := out.At(x, y).(color.RGBA64)
if color.R != 0x8000 || color.G != 0x8000 || color.B != 0x8000 || color.A != 0xFFFF {
t.Errorf("%+v", color)
}
}
}
}
// Resize an image to new width and height using the interpolation function interp.
// A new image with the given dimensions will be returned.
// If one of the parameters width or height is set to 0, its size will be calculated so that
// the aspect ratio is that of the originating image.
// The resizing algorithm uses channels for parallel computation.
func Resize(width, height uint, img image.Image, interp InterpolationFunction) image.Image {
oldBounds := img.Bounds()
oldWidth := float32(oldBounds.Dx())
oldHeight := float32(oldBounds.Dy())
scaleX, scaleY := calcFactors(width, height, oldWidth, oldHeight)
t := Trans2{scaleX, 0, float32(oldBounds.Min.X), 0, scaleY, float32(oldBounds.Min.Y)}
resizedImg := image.NewRGBA64(image.Rect(0, 0, int(0.7+oldWidth/scaleX), int(0.7+oldHeight/scaleY)))
b := resizedImg.Bounds()
adjustX := 0.5 * ((oldWidth-1.0)/scaleX - float32(b.Dx()-1))
adjustY := 0.5 * ((oldHeight-1.0)/scaleY - float32(b.Dy()-1))
n := numJobs(b.Dy())
c := make(chan int, n)
for i := 0; i < n; i++ {
go func(b image.Rectangle, c chan int) {
filter := interp(img, [2]float32{clampFactor(scaleX), clampFactor(scaleY)})
var u, v float32
var color color.RGBA64
for y := b.Min.Y; y < b.Max.Y; y++ {
for x := b.Min.X; x < b.Max.X; x++ {
u, v = t.Eval(float32(x)+adjustX, float32(y)+adjustY)
color = filter.Interpolate(u, v)
i := resizedImg.PixOffset(x, y)
resizedImg.Pix[i+0] = uint8(color.R >> 8)
resizedImg.Pix[i+1] = uint8(color.R)
resizedImg.Pix[i+2] = uint8(color.G >> 8)
resizedImg.Pix[i+3] = uint8(color.G)
resizedImg.Pix[i+4] = uint8(color.B >> 8)
resizedImg.Pix[i+5] = uint8(color.B)
resizedImg.Pix[i+6] = uint8(color.A >> 8)
resizedImg.Pix[i+7] = uint8(color.A)
}
}
c <- 1
}(image.Rect(b.Min.X, b.Min.Y+i*(b.Dy())/n, b.Max.X, b.Min.Y+(i+1)*(b.Dy())/n), c)
}
for i := 0; i < n; i++ {
<-c
}
return resizedImg
}
func (p *RadianceImage) ToRGBA64(iterations int) *image.RGBA64 {
scalefactor := p.calculateScaleFactor(iterations)
m := image.NewRGBA64(image.Rect(0, 0, p.Width, p.Height))
for x := 0; x < p.Width; x++ {
for y := 0; y < p.Height; y++ {
radiance := p.Get(x, y)
r := uint16(65535 * math.Pow(math.Max(radiance.R*scalefactor/float64(iterations), 0), GAMMA_ENCODE))
g := uint16(65535 * math.Pow(math.Max(radiance.G*scalefactor/float64(iterations), 0), GAMMA_ENCODE))
b := uint16(65535 * math.Pow(math.Max(radiance.B*scalefactor/float64(iterations), 0), GAMMA_ENCODE))
a := uint16(65535)
m.Set(x, y, color.RGBA64{r, g, b, a})
}
}
return m
}
func (pyr *Pyramid) Visualize() image.Image {
var width, height int
for _, level := range pyr.Levels {
if level.Bounds().Dx() > width {
width = level.Bounds().Dx()
}
height += level.Bounds().Dy()
}
im := image.NewRGBA64(image.Rect(0, 0, width, height))
var p image.Point
for _, level := range pyr.Levels {
draw.Draw(im, level.Bounds().Add(p), level, image.ZP, draw.Src)
p.Y += level.Bounds().Dy()
}
return im
}
// purpleJPEG takes in an image and makes each of pixels more purple by
// incrementing its red and blue hex values by 50.
func purpleJPEG(img image.Image) {
pixels := image.NewRGBA64(img.Bounds())
for x := pixels.Bounds().Min.X; x < pixels.Bounds().Max.X; x++ {
for y := pixels.Bounds().Min.Y; y < pixels.Bounds().Max.Y; y++ {
r, g, b, a := img.At(x, y).RGBA()
r = r>>8 + 50
b = b>>8 + 50
if r > 256 {
r = 256
}
if b > 256 {
b = 256
}
pixels.Set(x, y, color.RGBA64{R: uint16(r << 8), G: uint16(g), B: uint16(b << 8), A: uint16(a)})
}
}
jpeg.Encode(os.Stdout, pixels, nil)
}
func TestEncode64(t *testing.T) {
img := image.NewRGBA64(image.Rect(0, 0, 3, 3))
for x := 0; x < 3; x++ {
for y := 0; y < 3; y++ {
img.SetRGBA64(x, y, imagePixels64[y][x])
}
}
var buf bytes.Buffer
err := Encode(&buf, img)
if err != nil {
t.Fatal(err)
}
if !bytes.Equal(imageData, buf.Bytes()) {
t.Fatal("encoding error")
}
}
