func ImageEnhanceGrey(img *image.Gray, enhanceDegress float32, enhanceOffset float32) *image.RGBA {
rgbFunc := func(xpos, ypos int) (r0, g0, b0, a0 uint8) {
gray := img.GrayAt(xpos, ypos)
return gray.Y, gray.Y, gray.Y, gray.Y
}
imgEnhanced := imenhance(enhanceDegress, enhanceOffset, [3]bool{true, true, true}, false, img.Rect, rgbFunc)
return imgEnhanced
}
func emptyCol(m *image.Gray, r image.Rectangle, x int) bool {
for y := r.Min.Y; y < r.Max.Y; y++ {
if m.GrayAt(x, y).Y > 0 {
return false
}
}
return true
}
func emptyRow(m *image.Gray, r image.Rectangle, y int) bool {
for x := r.Min.X; x < r.Max.X; x++ {
if m.GrayAt(x, y).Y > 0 {
return false
}
}
return true
}
func meanHeight(g *image.Gray) uint8 {
b := g.Bounds()
var total uint64
for i := b.Min.X; i < b.Max.X; i++ {
for j := b.Min.Y; j < b.Max.Y; j++ {
total += uint64(g.GrayAt(i, j).Y)
}
}
return uint8(total / uint64((b.Dx() * b.Dy())))
}
// Transforms gray input image color depth to the palette defined in p
// The algorithm simply assigns the nearest palette color to each pixel,
// without distributing error in any way, so expect color banding
func ditheringAverage(img *image.Gray, p *color.Palette) {
size := img.Bounds()
for y := size.Min.Y; y < size.Max.Y; y++ {
for x := size.Min.X; x < size.Max.X; x++ {
c1 := img.GrayAt(x, y)
c2 := p.Convert(c1).(color.Gray)
img.SetGray(x, y, c2)
}
}
}
////////////////////////////////////////////////////////////////////////////////
// Does a top to bottom, left to right scan of img starting at x,y. When a //
// black pixel is encountered, the scan stops and the position is returned //
////////////////////////////////////////////////////////////////////////////////
func nextPixel(x, y int, img *image.Gray, vis []bool) (int, int) {
offset := img.Bounds().Max.X
for cy := y; cy < img.Bounds().Max.Y; cy++ {
start := 0
if cy == y {
start = x
}
for cx := start; cx < img.Bounds().Max.X; cx++ {
if !vis[cx+cy*offset] && img.GrayAt(cx, cy) == black {
return cx, cy
}
}
}
return -1, -1
}
func ImageFilterGrey(img *image.Gray, filter [][]float32, lowQuality bool) *image.RGBA {
if lowQuality {
imgAva := ImageEnhanceGrey(img, filter[0][0], 0)
return imfilter(filter, img.Rect, func(xpos, ypos int) (r0, g0, b0, a0 uint8) {
gray := imgAva.RGBAAt(xpos, ypos)
return gray.R, gray.R, gray.R, gray.A
}, func(filterValue, colorValue float32) float32 {
return colorValue
})
}
return imfilter(filter, img.Rect, func(xpos, ypos int) (r0, g0, b0, a0 uint8) {
gray := img.GrayAt(xpos, ypos)
return gray.Y, gray.Y, gray.Y, gray.Y
}, func(filterValue, colorValue float32) float32 {
return filterValue * colorValue
})
}
// RecogniseDigit takes 28x28 gray image and tries to recognise a digit
// panics if image has wrong size
func RecogniseDigit(img image.Gray, threshold uint8) (int, float64) {
if img.Bounds().Max.X != 28 || img.Bounds().Max.Y != 28 {
panic("Image size is invalid, use 28x28.")
}
input := make([]float64, 28*28, 28*28)
pos := 0
for x := 0; x < 28; x++ {
for y := 0; y < 28; y++ {
val := img.GrayAt(x, y).Y
if val < threshold {
val = 255 - val
} else {
val = 0
}
img.SetGray(x, y, color.Gray{Y: val})
input[pos] = float64(val) / 255
pos++
}
}
digit, confidence := argmax(nn.Evaluate(input))
return digit, confidence
}
func drawDroplet(img *image.Gray, x, y, r, h float64) {
ri := int(r + 1)
xi := int(x + 0.5)
yi := int(y + 0.5)
for i := yi - ri; i <= yi+ri; i++ {
for j := xi - ri; j <= xi+ri; j++ {
if i < 0 || i >= img.Rect.Dy() || j < 0 || j >= img.Rect.Dx() {
continue
}
di := float64(i) - y
dj := float64(j) - x
if rr := di*di + dj*dj; rr <= r*r {
vprev := img.GrayAt(j, i).Y
v := 100*h/r*math.Pow(1-rr/r/r, 1.0)/math.Sqrt(1-di/r) + float64(vprev)
if v > 255 {
v = 255
}
img.SetGray(j, i, color.Gray{uint8(v)})
}
}
}
}
// Dithering algorithms
// Dithering is the process of reducing the colorspace of an image to a more
// restricted palette. Since the Game Boy Printer only has a 2bit colorspace
// available, it's important that some dithering algorithms are implemented to
// deal with the fact. Depending on the properties of the dithering algorithm
// detail may or may not be preserved as well. Using simple techniques like
// average dithering will yield results with lots of color banding, while employing
// error diffusion techniques such as Floyd Steinberg will produce smoother
// results (color banding is replaced by the introduction of noise)
// The wikipedia article (http://en.wikipedia.org/wiki/Dither) is quite interesting
// and talks about some dithering algorithms, some of which are implemented here.
// Floyd Steinberg is an error diffusion dithering algorithm that adds the error
// of each color conversion to the neighbours of each pixel. This way it's possible
// to achieve a finer graded dithering
func ditheringFloydSteinberg(img *image.Gray, p *color.Palette) {
size := img.Bounds()
for y := size.Min.Y; y < size.Max.Y; y++ {
for x := size.Min.X; x < size.Max.X; x++ {
c1 := img.GrayAt(x, y)
c2 := p.Convert(c1).(color.Gray)
delta := int(c1.Y) - int(c2.Y)
switch {
case x+1 < size.Max.X && y < size.Max.Y:
img.SetGray(x+1, y, color.Gray{uint8(int(img.GrayAt(x+1, y).Y) + delta*7/16)})
fallthrough
case x < size.Max.X && y+1 < size.Max.Y:
img.SetGray(x, y+1, color.Gray{uint8(int(img.GrayAt(x, y+1).Y) + delta*5/16)})
fallthrough
case x-1 >= size.Min.X && y+1 < size.Max.Y:
img.SetGray(x-1, y+1, color.Gray{uint8(int(img.GrayAt(x-1, y+1).Y) + delta*3/16)})
fallthrough
case x+1 < size.Max.X && y+1 < size.Max.Y:
img.SetGray(x+1, y+1, color.Gray{uint8(int(img.GrayAt(x+1, y+1).Y) + delta*1/16)})
}
img.Set(x, y, c2)
}
}
}
func (g *generator) buildTerrain(mpath minecraft.Path, level *level, terrain, biomes, plants *image.Paletted, height, water *image.Gray, c chan paint) error {
b := terrain.Bounds()
proceed := make(chan uint8, 10)
errChan := make(chan error, 1)
go func() {
defer close(proceed)
cc := newCache(g.Terrain.Blocks)
for j := 0; j < b.Max.Y; j += 16 {
chunkZ := int32(j >> 4)
for i := 0; i < b.Max.X; i += 16 {
chunkX := int32(i >> 4)
h := int32(meanHeight(height.SubImage(image.Rect(i, j, i+16, j+16)).(*image.Gray)))
wh := int32(meanHeight(water.SubImage(image.Rect(i, j, i+16, j+16)).(*image.Gray)))
var t uint8
if wh >= h<<1 { // more water than land...
c <- paint{
color.RGBA{0, 0, 255, 255},
chunkX, chunkZ,
}
t = uint8(len(g.Terrain.Blocks) - 1)
h = wh
} else {
t = modeTerrain(terrain.SubImage(image.Rect(i, j, i+16, j+16)).(*image.Paletted), len(g.Terrain.Palette))
c <- paint{
g.Terrain.Palette[t],
chunkX, chunkZ,
}
}
if err := mpath.SetChunk(cc.getFromCache(chunkX, chunkZ, t, h)); err != nil {
errChan <- err
return
}
proceed <- t
}
}
}()
ts := make([]uint8, 0, 1024)
for i := 0; i < (b.Max.X>>4)+2; i++ {
ts = append(ts, <-proceed) // get far enough ahead so all chunks are surrounded before shaping, to get correct lighting
}
select {
case err := <-errChan:
return err
default:
}
for j := int32(0); j < int32(b.Max.Y); j += 16 {
chunkZ := j >> 4
for i := int32(0); i < int32(b.Max.X); i += 16 {
chunkX := i >> 4
var totalHeight int32
ot := ts[0]
ts = ts[1:]
oy, _ := level.GetHeight(i, j)
for x := i; x < i+16; x++ {
for z := j; z < j+16; z++ {
if biomes != nil {
level.SetBiome(x, z, g.Biomes.Values[biomes.ColorIndexAt(int(x), int(z))])
}
h := int32(height.GrayAt(int(x), int(z)).Y)
totalHeight += h
wl := int32(water.GrayAt(int(x), int(z)).Y)
y := oy
if h > y {
y = h
}
if wl > y {
y = wl
}
for ; y > h && y > wl; y-- {
level.SetBlock(x, y, z, minecraft.Block{})
}
if plants != nil {
p := g.Plants.Blocks[plants.ColorIndexAt(int(x), int(z))]
py := int32(1)
for ; py <= int32(p.Level); py++ {
level.SetBlock(x, y+py, z, p.Base)
}
level.SetBlock(x, y+py, z, p.Top)
}
for ; y > h; y-- {
level.SetBlock(x, y, z, minecraft.Block{ID: 9})
}
t := terrain.ColorIndexAt(int(x), int(z))
tb := g.Terrain.Blocks[t]
for ; y > h-int32(tb.Level); y-- {
level.SetBlock(x, y, z, tb.Top)
}
if t != ot {
h = 0
} else {
h = oy
}
for ; y >= h; y-- {
level.SetBlock(x, y, z, tb.Base)
}
}
}
c <- paint{
color.Alpha{uint8(totalHeight >> 8)},
chunkX, chunkZ,
}
select {
case p, ok := <-proceed:
if ok {
ts = append(ts, p)
}
case err := <-errChan:
return err
}
}
}
return nil
}
func TestDecode(t *testing.T) {
var j *image.Gray
i, _, _ := Decode("../att_faces/s1/1.png")
j = i.(*image.Gray)
fmt.Println(j.GrayAt(0, 0).Y)
}
func blobAt(x, y int, img *image.Gray, vis []bool) *Blob {
if img.GrayAt(x, y) == white {
return nil
}
width := img.Bounds().Max.X
height := img.Bounds().Max.Y
r := image.Rect(x, y, x, y)
q := newQueue()
q.q(point{x, y})
for q.length != 0 {
p := q.dq()
if vis[p.x+width*p.y] {
continue
}
vis[p.x+width*p.y] = true
if p.x > r.Max.X {
r.Max.X = p.x
}
if p.x < r.Min.X {
r.Min.X = p.x
}
if p.y > r.Max.Y {
r.Max.Y = p.y
}
if p.y < r.Min.Y {
r.Min.Y = p.y
}
// Up
if p.y-1 >= 0 {
if !vis[p.x+(p.y-1)*width] && img.GrayAt(p.x, p.y-1) == black {
q.q(point{p.x, p.y - 1})
}
}
// Right
if p.x+1 < width {
if !vis[p.x+1+p.y*width] && img.GrayAt(p.x+1, p.y) == black {
q.q(point{p.x + 1, p.y})
}
}
// Down
if p.y+1 < height {
if !vis[p.x+(p.y+1)*width] && img.GrayAt(p.x, p.y+1) == black {
q.q(point{p.x, p.y + 1})
}
}
// Left
if p.x-1 >= 0 {
if !vis[p.x-1+p.y*width] && img.GrayAt(p.x-1, p.y) == black {
q.q(point{p.x - 1, p.y})
}
}
}
r.Max.Y += 1
r.Max.X += 1
return &Blob{Bounds: r, Img: img.SubImage(r)}
}