dst = dst1
		} else {
			b.Fatal("unknown destination color model", dcm)
		}
	}

	var src image.Image
	switch scm {
	case nil:
		src = &image.Uniform{C: color.RGBA{0x11, 0x22, 0x33, 0x44}}
	case color.CMYKModel:
		src1 := image.NewCMYK(image.Rect(0, 0, srcw, srch))
		for y := 0; y < srch; y++ {
			for x := 0; x < srcw; x++ {
				src1.SetCMYK(x, y, color.CMYK{
					uint8(13 * x % 0x100),
					uint8(11 * y % 0x100),

	g := (0xffff - uint32(c.M)*0x101) * w / 0xffff
	b := (0xffff - uint32(c.Y)*0x101) * w / 0xffff
	return r, g, b, 0xffff
}

// CMYKModel is the [Model] for CMYK colors.
var CMYKModel Model = ModelFunc(cmykModel)

func cmykModel(c Color) Color {
	if _, ok := c.(CMYK); ok {
		return c
	}
	r, g, b, _ := c.RGBA()
	cc, mm, yy, kk := RGBToCMYK(uint8(r>>8), uint8(g>>8), uint8(b>>8))

	// Stride is the Pix stride (in bytes) between vertically adjacent pixels.
	Stride int
	// Rect is the image's bounds.
	Rect Rectangle
}

func (p *CMYK) ColorModel() color.Model { return color.CMYKModel }

func (p *CMYK) Bounds() Rectangle { return p.Rect }

func (p *CMYK) At(x, y int) color.Color {
	return p.CMYKAt(x, y)
}

func (p *CMYK) RGBA64At(x, y int) color.RGBA64 {

			cm = color.RGBAModel
		}
		return image.Config{
			ColorModel: cm,
			Width:      d.width,
			Height:     d.height,
		}, nil
	case 4:
		return image.Config{
			ColorModel: color.CMYKModel,
			Width:      d.width,
			Height:     d.height,
		}, nil
	}
	return image.Config{}, FormatError("missing SOF marker")
}

func init() {

pkg image/color, type CMYK struct, C uint8
pkg image/color, type CMYK struct, K uint8
pkg image/color, type CMYK struct, M uint8
pkg image/color, type CMYK struct, Y uint8
pkg image/color, var CMYKModel Model
pkg image/gif, const DisposalBackground = 2
pkg image/gif, const DisposalBackground ideal-int
pkg image/gif, const DisposalNone = 1
pkg image/gif, const DisposalNone ideal-int

		{"Alpha16Model", Var, 0},
		{"AlphaModel", Var, 0},
		{"Black", Var, 0},
		{"CMYK", Type, 5},
		{"CMYK.C", Field, 5},
		{"CMYK.K", Field, 5},
		{"CMYK.M", Field, 5},
		{"CMYK.Y", Field, 5},
		{"CMYKModel", Var, 5},
		{"CMYKToRGB", Func, 5},
		{"Color", Type, 0},
		{"Gray", Type, 0},
		{"Gray.Y", Field, 0},
		{"Gray16", Type, 0},
		{"Gray16.Y", Field, 0},
		{"Gray16Model", Var, 0},