Golang Paletted.Palette方法代碼示例

func (q *MedianCutQuantizer) Quantize(dst *image.Paletted, r image.Rectangle, src image.Image, sp image.Point) {
	clip(dst, &r, src, &sp)
	if r.Empty() {
		return
	}

	points := make([]point, r.Dx()*r.Dy())
	colorSet := make(map[uint32]color.Color, q.NumColor)
	i := 0
	for y := r.Min.Y; y < r.Max.Y; y++ {
		for x := r.Min.X; x < r.Max.X; x++ {
			c := src.At(x, y)
			r, g, b, _ := c.RGBA()
			colorSet[(r>>8)<<16|(g>>8)<<8|b>>8] = c
			points[i][0] = int(r)
			points[i][1] = int(g)
			points[i][2] = int(b)
			i++
		}
	}
	if len(colorSet) <= q.NumColor {
		// No need to quantize since the total number of colors
		// fits within the palette.
		dst.Palette = make(color.Palette, len(colorSet))
		i := 0
		for _, c := range colorSet {
			dst.Palette[i] = c
			i++
		}
	} else {
		dst.Palette = q.medianCut(points)
	}

	for y := 0; y < r.Dy(); y++ {
		for x := 0; x < r.Dx(); x++ {
			// TODO: this should be done more efficiently.
			dst.Set(sp.X+x, sp.Y+y, src.At(r.Min.X+x, r.Min.Y+y))
		}
	}
}

func ripShinyPokemonBack(rip *sprites.Ripper, number int, form string, outname string) error {
	var m *image.Paletted
	var err error
	if number == 201 && form != "" {
		m, err = rip.UnownBack(form)
	} else {
		m, err = rip.PokemonBack(number)
	}
	if err != nil {
		return err
	}
	m.Palette = rip.ShinyPalette(number)
	if m.Palette == nil {
		return errors.New("couldn't get palette")
	}
	return write(m, outname)
}

// Merge les deux images de telle sorte qu'après l'opération les pixels de img1 :
//   - soient inchangés là où l'index dans img2 est 0
//   - prennent la valeur de img2 ailleurs
// Les deux images doivent être de mêmes dimensions exactement
// La palette de img1 est enrichie si nécessaire
func Fusionne(img1 *image.Paletted, img2 *image.Paletted) error {
	r1 := img1.Bounds()
	r2 := img2.Bounds()
	if r1.Min.X != r2.Min.X || r1.Max.X != r2.Max.X || r1.Min.Y != r2.Min.Y || r1.Max.Y != r2.Max.Y {
		return errors.New("image dimensions not compatible")
	}
	p1 := img1.Palette
	p2 := img2.Palette
	n1 := len(p1)
	n2 := len(p2)
	op := make([]uint8, n2) // tableau donnant l'index dans la palette de img1 d'une couleur de la palette de img2
	for i2 := 0; i2 < n2; i2++ {
		c := p2[i2].(color.RGBA)
		if i2 < n1 && couleursEgales(c, p1[i2].(color.RGBA)) {
			op[i2] = uint8(i2)
		} else {
			found := false
			for i1 := 0; i1 < n1; i1++ {
				if couleursEgales(c, p1[i1].(color.RGBA)) {
					op[i2] = uint8(i1)
					found = true
					break
				}
			}
			if !found {
				op[i2] = uint8(len(p1))
				p1 = append(p1, c)
				img1.Palette = p1
			}
		}
	}
	l2 := len(img2.Pix)
	for x := 0; x < l2; x++ {
		if img2.Pix[x] != 0 {
			img1.Pix[x] = op[img2.Pix[x]]
		}
	}
	return nil
}

// decode decodes the IDAT data into an image.
func (d *decoder) decode() (image.Image, error) {
	r, err := zlib.NewReader(d)
	if err != nil {
		return nil, err
	}
	defer r.Close()
	bitsPerPixel := 0
	pixOffset := 0
	var (
		gray     *image.Gray
		rgba     *image.RGBA
		paletted *image.Paletted
		nrgba    *image.NRGBA
		gray16   *image.Gray16
		rgba64   *image.RGBA64
		nrgba64  *image.NRGBA64
		img      image.Image
	)
	switch d.cb {
	case cbG1, cbG2, cbG4, cbG8:
		bitsPerPixel = d.depth
		gray = image.NewGray(image.Rect(0, 0, d.width, d.height))
		img = gray
	case cbGA8:
		bitsPerPixel = 16
		nrgba = image.NewNRGBA(image.Rect(0, 0, d.width, d.height))
		img = nrgba
	case cbTC8:
		bitsPerPixel = 24
		rgba = image.NewRGBA(image.Rect(0, 0, d.width, d.height))
		img = rgba
	case cbP1, cbP2, cbP4, cbP8:
		bitsPerPixel = d.depth
		paletted = image.NewPaletted(image.Rect(0, 0, d.width, d.height), d.palette)
		img = paletted
	case cbTCA8:
		bitsPerPixel = 32
		nrgba = image.NewNRGBA(image.Rect(0, 0, d.width, d.height))
		img = nrgba
	case cbG16:
		bitsPerPixel = 16
		gray16 = image.NewGray16(image.Rect(0, 0, d.width, d.height))
		img = gray16
	case cbGA16:
		bitsPerPixel = 32
		nrgba64 = image.NewNRGBA64(image.Rect(0, 0, d.width, d.height))
		img = nrgba64
	case cbTC16:
		bitsPerPixel = 48
		rgba64 = image.NewRGBA64(image.Rect(0, 0, d.width, d.height))
		img = rgba64
	case cbTCA16:
		bitsPerPixel = 64
		nrgba64 = image.NewNRGBA64(image.Rect(0, 0, d.width, d.height))
		img = nrgba64
	}
	bytesPerPixel := (bitsPerPixel + 7) / 8

	// cr and pr are the bytes for the current and previous row.
	// The +1 is for the per-row filter type, which is at cr[0].
	cr := make([]uint8, 1+(bitsPerPixel*d.width+7)/8)
	pr := make([]uint8, 1+(bitsPerPixel*d.width+7)/8)

	for y := 0; y < d.height; y++ {
		// Read the decompressed bytes.
		_, err := io.ReadFull(r, cr)
		if err != nil {
			return nil, err
		}

		// Apply the filter.
		cdat := cr[1:]
		pdat := pr[1:]
		switch cr[0] {
		case ftNone:
			// No-op.
		case ftSub:
			for i := bytesPerPixel; i < len(cdat); i++ {
				cdat[i] += cdat[i-bytesPerPixel]
			}
		case ftUp:
			for i, p := range pdat {
				cdat[i] += p
			}
		case ftAverage:
			for i := 0; i < bytesPerPixel; i++ {
				cdat[i] += pdat[i] / 2
			}
			for i := bytesPerPixel; i < len(cdat); i++ {
				cdat[i] += uint8((int(cdat[i-bytesPerPixel]) + int(pdat[i])) / 2)
			}
		case ftPaeth:
			filterPaeth(cdat, pdat, bytesPerPixel)
		default:
			return nil, FormatError("bad filter type")
		}

		// Convert from bytes to colors.
		switch d.cb {
//.........這裏部分代碼省略.........

// decode reads a GIF image from r and stores the result in d.
func (d *decoder) decode(r io.Reader, configOnly bool) error {
	// Add buffering if r does not provide ReadByte.
	if rr, ok := r.(reader); ok {
		d.r = rr
	} else {
		d.r = bufio.NewReader(r)
	}

	err := d.readHeaderAndScreenDescriptor()
	if err != nil {
		return err
	}
	if configOnly {
		return nil
	}

	if d.headerFields&fColorMapFollows != 0 {
		if d.globalColorMap, err = d.readColorMap(); err != nil {
			return err
		}
	}

Loop:
	for err == nil {
		var c byte
		c, err = d.r.ReadByte()
		if err == io.EOF {
			break
		}
		switch c {
		case sExtension:
			err = d.readExtension()

		case sImageDescriptor:
			var m *image.Paletted
			m, err = d.newImageFromDescriptor()
			if err != nil {
				break
			}
			if d.imageFields&fColorMapFollows != 0 {
				m.Palette, err = d.readColorMap()
				if err != nil {
					break
				}
				// TODO: do we set transparency in this map too? That would be
				// d.setTransparency(m.Palette)
			} else {
				m.Palette = d.globalColorMap
			}
			var litWidth uint8
			litWidth, err = d.r.ReadByte()
			if err != nil {
				return err
			}
			if litWidth < 2 || litWidth > 8 {
				return fmt.Errorf("gif: pixel size in decode out of range: %d", litWidth)
			}
			// A wonderfully Go-like piece of magic.
			lzwr := lzw.NewReader(&blockReader{r: d.r}, lzw.LSB, int(litWidth))
			if _, err = io.ReadFull(lzwr, m.Pix); err != nil {
				break
			}

			// There should be a "0" block remaining; drain that.
			c, err = d.r.ReadByte()
			if err != nil {
				return err
			}
			if c != 0 {
				return errors.New("gif: extra data after image")
			}

			// Undo the interlacing if necessary.
			if d.imageFields&ifInterlace != 0 {
				uninterlace(m)
			}

			d.image = append(d.image, m)
			d.delay = append(d.delay, d.delayTime)
			d.delayTime = 0 // TODO: is this correct, or should we hold on to the value?

		case sTrailer:
			break Loop

		default:
			err = fmt.Errorf("gif: unknown block type: 0x%.2x", c)
		}
	}
	if err != nil {
		return err
	}
	if len(d.image) == 0 {
		return io.ErrUnexpectedEOF
	}
	return nil
}

// readImagePass reads a single image pass, sized according to the pass number.
func (d *decoder) readImagePass(r io.Reader, pass int, allocateOnly bool) (image.Image, error) {
	var bitsPerPixel int = 0
	pixOffset := 0
	var (
		gray     *image.Gray
		rgba     *image.RGBA
		paletted *image.Paletted
		nrgba    *image.NRGBA
		gray16   *image.Gray16
		rgba64   *image.RGBA64
		nrgba64  *image.NRGBA64
		img      image.Image
	)
	width, height := d.width, d.height
	if d.interlace == itAdam7 && !allocateOnly {
		p := interlacing[pass]
		// Add the multiplication factor and subtract one, effectively rounding up.
		width = (width - p.xOffset + p.xFactor - 1) / p.xFactor
		height = (height - p.yOffset + p.yFactor - 1) / p.yFactor
		// A PNG image can't have zero width or height, but for an interlaced
		// image, an individual pass might have zero width or height. If so, we
		// shouldn't even read a per-row filter type byte, so return early.
		if width == 0 || height == 0 {
			return nil, nil
		}
	}
	switch d.cb {
	case cbG1, cbG2, cbG4, cbG8:
		bitsPerPixel = d.depth
		gray = image.NewGray(image.Rect(0, 0, width, height))
		img = gray
	case cbGA8:
		bitsPerPixel = 16
		nrgba = image.NewNRGBA(image.Rect(0, 0, width, height))
		img = nrgba
	case cbTC8:
		bitsPerPixel = 24
		rgba = image.NewRGBA(image.Rect(0, 0, width, height))
		img = rgba
	case cbP1, cbP2, cbP4, cbP8:
		bitsPerPixel = d.depth
		paletted = image.NewPaletted(image.Rect(0, 0, width, height), d.palette)
		img = paletted
	case cbTCA8:
		bitsPerPixel = 32
		nrgba = image.NewNRGBA(image.Rect(0, 0, width, height))
		img = nrgba
	case cbG16:
		bitsPerPixel = 16
		gray16 = image.NewGray16(image.Rect(0, 0, width, height))
		img = gray16
	case cbGA16:
		bitsPerPixel = 32
		nrgba64 = image.NewNRGBA64(image.Rect(0, 0, width, height))
		img = nrgba64
	case cbTC16:
		bitsPerPixel = 48
		rgba64 = image.NewRGBA64(image.Rect(0, 0, width, height))
		img = rgba64
	case cbTCA16:
		bitsPerPixel = 64
		nrgba64 = image.NewNRGBA64(image.Rect(0, 0, width, height))
		img = nrgba64
	}
	if allocateOnly {
		return img, nil
	}
	bytesPerPixel := (bitsPerPixel + 7) / 8

	// The +1 is for the per-row filter type, which is at cr[0].
	rowSize := 1 + (bitsPerPixel*width+7)/8
	// cr and pr are the bytes for the current and previous row.
	cr := make([]uint8, rowSize)
	pr := make([]uint8, rowSize)

	for y := 0; y < height; y++ {
		// Read the decompressed bytes.
		_, err := io.ReadFull(r, cr)
		if err != nil {
			if err == io.EOF || err == io.ErrUnexpectedEOF {
				return nil, FormatError("not enough pixel data")
			}
			return nil, err
		}

		// Apply the filter.
		cdat := cr[1:]
		pdat := pr[1:]
		switch cr[0] {
		case ftNone:
			// No-op.
		case ftSub:
			for i := bytesPerPixel; i < len(cdat); i++ {
				cdat[i] += cdat[i-bytesPerPixel]
			}
		case ftUp:
			for i, p := range pdat {
				cdat[i] += p
			}
//.........這裏部分代碼省略.........

// dessine la couche sur l'image qui peut avoir une palette différente de la palette standard.
func dessine(img *image.Paletted, couche *Couche) {
	imgIndexes := make(map[string]uint8)   // similaire à indexes (fond->index) mais relatif à la palette de l'image et non à la palette standard
	caseAPalissade := make(map[int32]bool) // map suivant PosKey(x,y) : true ssi une palissade est en x,y
	for _, p := range couche.Palissades {
		caseAPalissade[PosKey(p.X, p.Y)] = true
	}
	imgPalette := img.Palette
	déplacementsDansPalette := 0
	ajoutsPalette := 0
	n := len(imgPalette)
	nbAbsences := make(map[string]uint) // je note les fonds manquants dans ma palette, ils peuvent correspondre à des évolutions du jeu Braldahim
	for _, c := range couche.Cases {
		x, y := int(c.X)+SEMI_LARGEUR, SEMI_HAUTEUR-int(c.Y)
		key := c.Fond
		if caseAPalissade[PosKey(c.X, c.Y)] {
			key += ".p"
		}
		imgIndex, ok := imgIndexes[key] // index de la couleur du fond dans la palette de l'image
		if !ok {
			index, ok := indexes[key]
			if ok {
				c := palette[index].(color.RGBA)
				if index < uint8(n) && couleursEgales(c, imgPalette[index].(color.RGBA)) { // test rapide : si la couleur est au même index dans imgPalette que dans la palette standard
					imgIndex = index
					imgIndexes[key] = imgIndex
				} else {
					found := false
					for i := 0; i < n; i++ {
						if couleursEgales(c, imgPalette[i].(color.RGBA)) {
							found = true
							imgIndex = uint8(i)
							imgIndexes[key] = imgIndex
							break
						}
					}
					if found {
						déplacementsDansPalette++
					} else {
						log.Printf(" couleur \"%s\" absente de la palette de l'image\n", key)
						imgIndex = uint8(len(imgPalette))
						imgIndexes[key] = imgIndex
						img.Palette = append(img.Palette, c)
						imgPalette = img.Palette
						ajoutsPalette++
					}
				}
			} else { // fond inconnu y compris pour la palette standard
				nbAbsences[c.Fond] = nbAbsences[c.Fond] + 1
			}
		}
		img.SetColorIndex(x, y, imgIndex) // si pas ok, ça doit passer transparent (imgIndex=0)
	}
	if ajoutsPalette+déplacementsDansPalette != 0 {
		log.Println(" Transformations palette : ", déplacementsDansPalette, " déplacements et ", ajoutsPalette, "ajouts")
	}
	if len(nbAbsences) != 0 {
		log.Println(" Fonds manquants :")
		for fond, nb := range nbAbsences {
			log.Println(" ", fond, " : ", nb)
		}
	}
}