func (p *YCbCr) RGBA64At(x, y int) color.RGBA64 {
	r, g, b, a := p.YCbCrAt(x, y).RGBA()
	return color.RGBA64{uint16(r), uint16(g), uint16(b), uint16(a)}
}

func (p *YCbCr) YCbCrAt(x, y int) color.YCbCr {
	if !(Point{x, y}.In(p.Rect)) {
		return color.YCbCr{}
	}
	yi := p.YOffset(x, y)
	ci := p.COffset(x, y)
	return color.YCbCr{
		p.Y[yi],
		p.Cb[ci],
		p.Cr[ci],
	}
}

}

// YCbCrModel is the [Model] for Y'CbCr colors.
var YCbCrModel Model = ModelFunc(yCbCrModel)

func yCbCrModel(c Color) Color {
	if _, ok := c.(YCbCr); ok {
		return c
	}
	r, g, b, _ := c.RGBA()
	y, u, v := RGBToYCbCr(uint8(r>>8), uint8(g>>8), uint8(b>>8))
	return YCbCr{y, u, v}
}

// NYCbCrA represents a non-alpha-premultiplied Y'CbCr-with-alpha color, having

	for i := 0; i < 256; i++ {
		c0 := NYCbCrA{YCbCr{0xff, 0x80, 0x80}, uint8(i)}
		c1 := Alpha{uint8(i)}
		if err := eq(c0, c1); err != nil {
			t.Errorf("i=0x%02x:\n%v", i, err)
		}
	}
}

// TestNYCbCrAYCbCr tests that NYCbCrA colors are a superset of YCbCr colors.
func TestNYCbCrAYCbCr(t *testing.T) {
	for i := 0; i < 256; i++ {
		c0 := NYCbCrA{YCbCr{uint8(i), 0x40, 0xc0}, 0xff}
		c1 := YCbCr{uint8(i), 0x40, 0xc0}

		log.Fatal(err)
	}
}

const pre = `// Code generated by go run gen.go; DO NOT EDIT.

package imageutil

import (
	"image"
)

// DrawYCbCr draws the YCbCr source image on the RGBA destination image with
// r.Min in dst aligned with sp in src. It reports whether the draw was
// successful. If it returns false, no dst pixels were changed.
//

	default:
		rgba, _ := m.(*image.RGBA)
		ycbcr, _ := m.(*image.YCbCr)
		for y := bounds.Min.Y; y < bounds.Max.Y; y += 16 {
			for x := bounds.Min.X; x < bounds.Max.X; x += 16 {
				for i := 0; i < 4; i++ {
					xOff := (i & 1) * 8
					yOff := (i & 2) * 4
					p := image.Pt(x+xOff, y+yOff)
					if rgba != nil {
						rgbaToYCbCr(rgba, p, &b, &cb[i], &cr[i])
					} else if ycbcr != nil {

	for _, c := range colors {
		var dst any
		switch c.Space {
		case "RGB":
			dst = new(RGB)
		case "YCbCr":
			dst = new(YCbCr)
		}
		err := json.Unmarshal(c.Point, dst)
		if err != nil {
			log.Fatalln("error:", err)
		}
		fmt.Println(c.Space, dst)
	}
	// Output:
	// YCbCr &{255 0 -10}
	// RGB &{98 218 255}
}

// This example uses RawMessage to use a precomputed JSON during marshal.

					subRect := Rect(x0, y0, x1, y1)
					sub := m.SubImage(subRect).(*YCbCr)

					// For each point in the sub-image's bounds, check that m.At(x, y) equals sub.At(x, y).
					for y := sub.Rect.Min.Y; y < sub.Rect.Max.Y; y++ {
						for x := sub.Rect.Min.X; x < sub.Rect.Max.X; x++ {
							color0 := m.At(x, y).(color.YCbCr)
							color1 := sub.At(x, y).(color.YCbCr)
							if color0 != color1 {

// Code generated by go run gen.go; DO NOT EDIT.

package imageutil

import (
	"image"
)

// DrawYCbCr draws the YCbCr source image on the RGBA destination image with
// r.Min in dst aligned with sp in src. It reports whether the draw was
// successful. If it returns false, no dst pixels were changed.
//
// This function assumes that r is entirely within dst's bounds and the
// translation of r from dst coordinate space to src coordinate space is

		}:
			tc.SetRGBA64(1, 1, color.RGBA64{0x7FFF, 0x3FFF, 0x0000, 0x7FFF})

		case *NYCbCrA:
			memset(tc.YCbCr.Y, 0x77)
			memset(tc.YCbCr.Cb, 0x88)
			memset(tc.YCbCr.Cr, 0x99)
			memset(tc.A, 0xAA)

		case *Uniform:
			tc.C = color.RGBA64{0x7FFF, 0x3FFF, 0x0000, 0x7FFF}

		case *YCbCr:
			memset(tc.Y, 0x77)
			memset(tc.Cb, 0x88)
			memset(tc.Cr, 0x99)

		case Rectangle:

	"image/color.Gray":    true,
	"image/color.NRGBA64": true,
	"image/color.NRGBA":   true,
	"image/color.NYCbCrA": true,
	"image/color.RGBA64":  true,
	"image/color.RGBA":    true,
	"image/color.YCbCr":   true,
	"image.Point":         true,
	"image.Rectangle":     true,
	"image.Uniform":       true,

	"unicode.Range16": true,
	"unicode.Range32": true,