func writeImagePng(filename string, pixels []float32, xres, yres int) {
outImage := image.NewNRGBA(image.Rect(0, 0, xres, yres))
to_byte := func(v float32) uint8 {
// apply gamma and convert to 0..255
return uint8(Clamp(255.0*math.Pow(float64(v), 1.0/2.2), 0.0, 255.0))
}
for y := 0; y < yres; y++ {
for x := 0; x < xres; x++ {
var fcolor color.NRGBA
fcolor.R = to_byte(pixels[3*(y*xres+x)+0])
fcolor.G = to_byte(pixels[3*(y*xres+x)+1])
fcolor.B = to_byte(pixels[3*(y*xres+x)+2])
fcolor.A = 0xff
outImage.Set(x, y, fcolor)
}
}
f, err := os.Create(filename)
defer f.Close()
if err != nil {
Error("Error writing PNG \"%s\"", filename)
} else {
png.Encode(f, outImage)
}
}
func hexToColorNRGBA(hex string) color.NRGBA {
c := color.NRGBA{}
getIntensity := func(str string) uint8 {
if u, err := hexToUint8(str); err == nil {
return u
}
return 0
}
if len(hex) >= 6 {
c.R = getIntensity(hex[0:2])
c.G = getIntensity(hex[2:4])
c.B = getIntensity(hex[4:6])
}
if len(hex) == 8 {
c.A = getIntensity(hex[6:8])
} else {
c.A = 255
}
return c
}
// render one row of pixels by calculating a colour for each pixel.
// The image pixel row number is r. Fill the pixel colour into the
// image after the colour has been calculated.
func (r row) render(rt *rtrace, a, b, c lin.V3, img *image.NRGBA, seed *uint32) {
rgba := color.NRGBA{0, 0, 0, 255}
t, v1, v2 := lin.NewV3(), lin.NewV3(), lin.NewV3() // temp vectors.
colour, orig, dir := lin.NewV3(), lin.NewV3(), lin.NewV3()
for x := (rt.iw - 1); x >= 0; x-- {
colour.SetS(13, 13, 13) // Use a very dark default colour.
// Cast 64 rays per pixel for blur (stochastic sampling) and soft-shadows.
for cnt := 0; cnt < 64; cnt++ {
// Add randomness to the camera origin 17,16,8
t.Scale(&a, rnd(seed)-0.5).Scale(t, 99).Add(t, v1.Scale(&b, rnd(seed)-0.5).Scale(v1, 99))
orig.SetS(17, 16, 8).Add(orig, t)
// Add randomness to the camera direction.
rnda := rnd(seed) + float64(x)
rndb := float64(r) + rnd(seed)
dir.Scale(t, -1)
dir.Add(dir, v1.Scale(&a, rnda).Add(v1, v2.Scale(&b, rndb)).Add(v1, &c).Scale(v1, 16))
dir.Unit()
// accumulate the colour from each of the 64 rays.
sample := rt.sample(*orig, *dir, seed)
colour = sample.Scale(&sample, 3.5).Add(&sample, colour)
}
// set the final pixel colour in the image.
rgba.R = byte(colour.X) // red
rgba.G = byte(colour.Y) // green
rgba.B = byte(colour.Z) // blue
img.SetNRGBA(rt.iw-x, int(r), rgba)
}
}
func setRandomBrightness(c *color.NRGBA, max uint8) {
minc := min3(c.R, c.G, c.B)
maxc := max3(c.R, c.G, c.B)
if maxc > max {
return
}
n := rand.Intn(int(max-maxc)) - int(minc)
c.R = uint8(int(c.R) + n)
c.G = uint8(int(c.G) + n)
c.B = uint8(int(c.B) + n)
}
func drawMotionMap(ske0, ske1 *image.NRGBA, m *MotionMap, shift *ShiftMap) (img *image.RGBA) {
bounds := ske0.Bounds().Intersect(ske1.Bounds()).Intersect(m.Bounds)
if shift != nil {
bounds = bounds.Intersect(shift.Bounds)
}
s := 10
img = image.NewRGBA(image.Rectangle{bounds.Min.Mul(s), bounds.Max.Mul(s)})
gc := draw2d.NewGraphicContext(img)
for y := img.Bounds().Min.Y; y < img.Bounds().Max.Y; y++ {
for x := img.Bounds().Min.X; x < img.Bounds().Max.X; x++ {
c := color.NRGBA{255, 255, 255, 255}
if ske0.At(x/s, y/s).(color.NRGBA).A > 0 {
c.R = 0
}
if ske1.At(x/s, y/s).(color.NRGBA).A > 0 {
c.G = 0
}
img.Set(x, y, c)
}
}
count := 0
for y := m.Bounds.Min.Y; y < m.Bounds.Max.Y; y++ {
for x := m.Bounds.Min.X; x < m.Bounds.Max.X; x++ {
v := GetMotion(m, x, y)
if v.X != 0 || v.Y != 0 {
cx, cy := x*s+s/2, y*s+s/2
dx, dy := v.X*s, v.Y*s
gc.SetStrokeColor(color.RGBA{0, 0, 0, 255})
gc.MoveTo(float64(cx), float64(cy))
gc.LineTo(float64(cx+dx), float64(cy+dy))
gc.Stroke()
count++
}
if shift != nil {
sv := GetShift(shift, x, y)
if sv.Dx != 0.0 || sv.Dy != 0.0 {
cx, cy := x*s+s/2, y*s+s/2
sf := float64(s)
//fmt.Println(x, y, sv)
gc.SetStrokeColor(color.RGBA{0, 200, 0, 255})
gc.MoveTo(float64(cx), float64(cy))
gc.LineTo(float64(cx)+sv.Dx*sf, float64(cy)+sv.Dy*sf)
gc.Stroke()
}
}
}
}
fmt.Println("count:", count)
return
}
// Compare compares a and b using pdiff algorithm.
func (d *perceptual) Compare(a, b image.Image) (image.Image, int, error) {
ab, bb := a.Bounds(), b.Bounds()
w, h := ab.Dx(), ab.Dy()
if w != bb.Dx() || h != bb.Dy() {
return nil, -1, ErrSize
}
diff := image.NewNRGBA(image.Rect(0, 0, w, h))
var (
wg sync.WaitGroup
aLAB, bLAB [][]*labColor
aLap, bLap [][][]float64
)
wg.Add(2)
go func() {
aLAB, aLap = labLap(a, d.gamma, d.lum)
wg.Done()
}()
go func() {
bLAB, bLap = labLap(b, d.gamma, d.lum)
wg.Done()
}()
cpd := make([]float64, lapLevels) // cycles per degree
cpd[0] = 0.5 * float64(w) / d.odp // 0.5 * pixels per degree
for i := 1; i < lapLevels; i++ {
cpd[i] = 0.5 * cpd[i-1]
}
csfMax := csf(3.248, 100.0)
freq := make([]float64, lapLevels-2)
for i := 0; i < lapLevels-2; i++ {
freq[i] = csfMax / csf(cpd[i], 100.0)
}
wg.Wait()
var npix int // num of diff pixels
for y := 0; y < h; y++ {
for x := 0; x < w; x++ {
adapt := math.Max(0.5*(aLap[d.ai][y][x]+bLap[d.ai][y][x]), 1e-5)
mask := make([]float64, lapLevels-2)
contrast := make([]float64, lapLevels-2)
var contrastSum float64
for i := 0; i < lapLevels-2; i++ {
n1 := math.Abs(aLap[i][y][x] - aLap[i+1][y][x])
n2 := math.Abs(bLap[i][y][x] - bLap[i+1][y][x])
d1 := math.Abs(aLap[i+2][y][x])
d2 := math.Abs(bLap[i+2][y][x])
d := math.Max(d1, d2)
contrast[i] = math.Max(n1, n2) / math.Max(d, 1e-5)
mask[i] = vmask(contrast[i] * csf(cpd[i], adapt))
contrastSum += contrast[i]
}
if contrastSum < 1e-5 {
contrastSum = 1e-5
}
var factor float64
for i := 0; i < lapLevels-2; i++ {
factor += contrast[i] * freq[i] * mask[i] / contrastSum
}
if factor < 1 {
factor = 1
} else if factor > 10 {
factor = 10
}
delta := math.Abs(aLap[0][y][x] - bLap[0][y][x])
pass := true
// pure luminance test
if delta > factor*tvi(adapt) {
pass = false
} else if !d.nocolor {
// CIE delta E test with modifications
cf := d.cf
// ramp down the color test in scotopic regions
if adapt < 10.0 {
// don't do color test at all
cf = 0.0
}
da := aLAB[y][x].a - bLAB[y][x].a
db := aLAB[y][x].b - bLAB[y][x].b
if (da*da+db*db)*cf > factor {
pass = false
}
}
c := color.NRGBA{0, 0, 0, 0xff}
if !pass {
npix++
c.R = 0xff
//ar, ag, ab, _ := a.At(x, y).RGBA()
//br, bg, bb, _ := b.At(x, y).RGBA()
//c.R = uint8((math.Abs(float64(ar)-float64(br)) / 0xffff) * 0xff)
//c.G = uint8((math.Abs(float64(ag)-float64(bg)) / 0xffff) * 0xff)
//c.B = uint8((math.Abs(float64(ab)-float64(bb)) / 0xffff) * 0xff)
}
diff.Set(x, y, c)
}
}
return diff, npix, nil
}