Golang image.NewNRGBA函數代碼示例

//水印
func waterMark(picBytes []byte) []byte {
	// 打開水印圖並解碼
	img, fileType, _ := image.Decode(bytes.NewBuffer(picBytes))

	//讀取水印圖片
	watermark, _ := png.Decode(bytes.NewBuffer(wm))

	//原始圖界限
	origin_size := img.Bounds()

	//創建新圖層
	canvas := image.NewNRGBA(origin_size)

	//貼原始圖
	draw.Draw(canvas, origin_size, img, image.ZP, draw.Src)
	//貼水印圖
	draw.Draw(canvas, watermark.Bounds().Add(image.Pt(origin_size.Dx()-watermark.Bounds().Dx(), origin_size.Dy()-watermark.Bounds().Dy()-4)), watermark, image.ZP, draw.Over)

	//生成新圖片
	buff := bytes.NewBuffer([]byte{})

	switch fileType {
	case "jpeg":
		jpeg.Encode(buff, canvas, &jpeg.Options{95})
	default:
		png.Encode(buff, canvas)
	}

	return buff.Bytes()
}

// Sets skin.Processed to an isometric render of the head from a top-left angle (showing 3 sides).
func (skin *mcSkin) GetCube(width int) error {
	// Crop out the top of the head
	topFlat := imaging.Crop(skin.Image, image.Rect(8, 0, 16, 8))
	// Resize appropriately, so that it fills the `width` when rotated 45 def.
	topFlat = imaging.Resize(topFlat, int(float64(width)*math.Sqrt(2)/3+1), 0, imaging.NearestNeighbor)
	// Create the Gift filter
	filter := gift.New(
		gift.Rotate(45, color.Transparent, gift.LinearInterpolation),
	)
	bounds := filter.Bounds(topFlat.Bounds())
	top := image.NewNRGBA(bounds)
	// Draw it on the filter, then smush it!
	filter.Draw(top, topFlat)
	top = imaging.Resize(top, width+2, width/3, imaging.NearestNeighbor)
	// Skew the front and sides at 15 degree angles to match up with the
	// head that has been smushed
	front := skin.cropHead(skin.Image).(*image.NRGBA)
	side := imaging.Crop(skin.Image, image.Rect(0, 8, 8, 16))
	front = imaging.Resize(front, width/2, int(float64(width)/1.75), imaging.NearestNeighbor)
	side = imaging.Resize(side, width/2, int(float64(width)/1.75), imaging.NearestNeighbor)
	front = skewVertical(front, math.Pi/12)
	side = skewVertical(imaging.FlipH(side), math.Pi/-12)

	// Create a new image to assemble upon
	skin.Processed = image.NewNRGBA(image.Rect(0, 0, width, width))
	// Draw each side
	draw.Draw(skin.Processed.(draw.Image), image.Rect(0, width/6, width/2, width), side, image.Pt(0, 0), draw.Src)
	draw.Draw(skin.Processed.(draw.Image), image.Rect(width/2, width/6, width, width), front, image.Pt(0, 0), draw.Src)
	// Draw the top we created
	draw.Draw(skin.Processed.(draw.Image), image.Rect(-1, 0, width+1, width/3), top, image.Pt(0, 0), draw.Over)

	return nil
}

func rotate(im image.Image, angle int) image.Image {
	var rotated *image.NRGBA
	// trigonometric (i.e counter clock-wise)
	switch angle {
	case 90:
		newH, newW := im.Bounds().Dx(), im.Bounds().Dy()
		rotated = image.NewNRGBA(image.Rect(0, 0, newW, newH))
		for y := 0; y < newH; y++ {
			for x := 0; x < newW; x++ {
				rotated.Set(x, y, im.At(newH-1-y, x))
			}
		}
	case -90:
		newH, newW := im.Bounds().Dx(), im.Bounds().Dy()
		rotated = image.NewNRGBA(image.Rect(0, 0, newW, newH))
		for y := 0; y < newH; y++ {
			for x := 0; x < newW; x++ {
				rotated.Set(x, y, im.At(y, newW-1-x))
			}
		}
	case 180, -180:
		newW, newH := im.Bounds().Dx(), im.Bounds().Dy()
		rotated = image.NewNRGBA(image.Rect(0, 0, newW, newH))
		for y := 0; y < newH; y++ {
			for x := 0; x < newW; x++ {
				rotated.Set(x, y, im.At(newW-1-x, newH-1-y))
			}
		}
	default:
		return im
	}
	return rotated
}

func (this *Signer) GetMoreLineImage(text string, text_color image.Image, l int, fix_top, fix_bottom int) (image.Image, error) {
	r := image.Rect(0, 0, 414, 96)
	img := image.NewNRGBA(r)
	c := freetype.NewContext()
	c.SetDPI(this.Dpi)
	c.SetFont(this.font)
	c.SetFontSize(this.FontSize)
	c.SetClip(img.Bounds())
	c.SetDst(img)
	c.SetSrc(text_color)

	//pt := freetype.Pt(0, 0)
	pt := freetype.Pt(0, 0+int(c.PointToFix32(this.FontSize)>>8))
	var err error
	limit := c.PixToFix32(l)
	str := strings.Split(text, "\r\n")
	for i, s := range str {
		pt, err = c.DrawString(s, pt, limit)
		if err != nil {
			fmt.Println("c.DrawString(%s) error(%v)", s, err)
			return nil, err
		}
		if i < len(str)-1 {
			pt.Y += c.PointToFix32(this.FontSize * 1.5)
		}
	}
	x, y := l, c.Fix32ToPix(pt.Y)
	sub_r := image.Rect(0, 0, x+20, y+(fix_bottom-fix_top))

	sub_img := image.NewNRGBA(sub_r)
	draw.Draw(sub_img, sub_r, img, image.Point{0, fix_top}, draw.Src)
	return sub_img, nil
}

// imgの片方の辺をずらして変形する
// (option=trueで縦/falseで橫に伸ばす/option2=trueで左上固定/falseで右下固定)
// ＿　　　 ＿
// | |　→ / /
// ￣　　　￣
//
func Slide(img *image.Image, length int, option bool, option2 bool) image.Image {
	size := (*img).Bounds().Size()
	//橫を伸ばす場合は橫の長さがx+x/lenになる
	img2 := image.NewNRGBA(image.Rect(0, 0, size.X+int(float64(size.X)/float64(length)), size.Y))
	if option {
		//縦を伸ばす場合は縦の長さがx+x/lenになる
		img2 = image.NewNRGBA(image.Rect(0, 0, size.X, size.Y+int(float64(size.Y)/float64(length))))
	}
	size2 := (*img2).Bounds().Size()
	//統一で扱うために長い方を取得
	sizeB := size2.Y
	if size2.X > size2.Y {
		sizeB = size2.X
	}

	offset := 0
	for x, x2 := 0, 0; x < sizeB; x++ {
		//逆スタートの場合は反転
		x2 = x
		if option2 {
			if option {
				x2 = size2.X - x
			} else {
				x2 = size2.Y - x
			}
		}

		for y, y2 := 0, 0; y < sizeB; y++ {
			//逆スタートの場合は反転
			y2 = y
			if option2 {
				if option {
					y2 = size2.Y - y
				} else {
					y2 = size2.X - y
				}
			}

			c := (*img).At(x2, y2)
			r, g, b, _ := c.RGBA()
			if !(r == 0 && g == 0 && b == 0) {
				//縦橫の入れ替えの場合
				if option {
					img2.Set(x2, y2+offset, c)
				} else {
					img2.Set(y2+offset, x2, c)
				}
			}
		}

		//ずらす分
		if x2%length == 0 {
			offset++
		}
	}
	return img2
}

func BenchmarkPCompare(b *testing.B) {
	m1 := image.NewNRGBA(image.Rect(0, 0, 100, 100))
	m2 := image.NewNRGBA(image.Rect(0, 0, 100, 100))
	d := NewDefaultPerceptual()
	b.RunParallel(func(pb *testing.PB) {
		for pb.Next() {
			d.Compare(m1, m2)
		}
	})
}

func TestEncodeDecode(t *testing.T) {
	imgWithAlpha := image.NewNRGBA(image.Rect(0, 0, 3, 3))
	imgWithAlpha.Pix = []uint8{
		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
		127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138,
		244, 245, 246, 247, 248, 249, 250, 252, 252, 253, 254, 255,
	}

	imgWithoutAlpha := image.NewNRGBA(image.Rect(0, 0, 3, 3))
	imgWithoutAlpha.Pix = []uint8{
		0, 1, 2, 255, 4, 5, 6, 255, 8, 9, 10, 255,
		127, 128, 129, 255, 131, 132, 133, 255, 135, 136, 137, 255,
		244, 245, 246, 255, 248, 249, 250, 255, 252, 253, 254, 255,
	}

	for _, format := range []Format{JPEG, PNG, GIF, BMP, TIFF} {
		img := imgWithoutAlpha
		if format == PNG {
			img = imgWithAlpha
		}

		buf := &bytes.Buffer{}
		err := Encode(buf, img, format)
		if err != nil {
			t.Errorf("fail encoding format %s", format)
			continue
		}

		img2, err := Decode(buf)
		if err != nil {
			t.Errorf("fail decoding format %s", format)
			continue
		}
		img2cloned := Clone(img2)

		delta := 0
		if format == JPEG {
			delta = 3
		} else if format == GIF {
			delta = 16
		}

		if !compareNRGBA(img, img2cloned, delta) {
			t.Errorf("test [DecodeEncode %s] failed: %#v %#v", format, img, img2cloned)
			continue
		}
	}

	buf := &bytes.Buffer{}
	err := Encode(buf, imgWithAlpha, Format(100))
	if err != ErrUnsupportedFormat {
		t.Errorf("expected ErrUnsupportedFormat")
	}
}

func TestNrgbaPlanes(t *testing.T) {
	w, h := 256, 256
	src := readImage(t, "testdata/nrgba.png")
	ref := image.NewNRGBA(src.Bounds())
	err := Convert(ref, src, nil)
	expect(t, err, nil)
	raw := image.NewNRGBA(image.Rect(0, 0, w*2, h*2))
	dst := raw.SubImage(image.Rect(7, 7, 7+w, 7+h))
	err = Convert(dst, src, NewBicubicFilter())
	expect(t, err, nil)
	err = Convert(src, dst, NewBicubicFilter())
	expect(t, err, nil)
	checkPsnrs(t, ref, src, image.Rectangle{}, []float64{39})
}

func NewImageOfTypeRect(src image.Image, bounds image.Rectangle) image.Image {
	switch i := src.(type) {
	case *image.Alpha:
		return image.NewAlpha(bounds)
	case *image.Alpha16:
		return image.NewAlpha16(bounds)
	case *image.Gray:
		return image.NewGray(bounds)
	case *image.Gray16:
		return image.NewGray16(bounds)
	case *image.NRGBA:
		return image.NewNRGBA(bounds)
	case *image.NRGBA64:
		return image.NewNRGBA64(bounds)
	case *image.Paletted:
		return image.NewPaletted(bounds, i.Palette)
	case *image.RGBA:
		return image.NewRGBA(bounds)
	case *image.RGBA64:
		return image.NewRGBA64(bounds)
	case *image.YCbCr:
		return image.NewYCbCr(bounds, i.SubsampleRatio)
	}
	panic("Unknown image type")
}

func (t testTransport) RoundTrip(req *http.Request) (*http.Response, error) {
	var raw string

	switch req.URL.Path {
	case "/ok":
		raw = "HTTP/1.1 200 OK\n\n"
	case "/error":
		return nil, errors.New("http protocol error")
	case "/nocontent":
		raw = "HTTP/1.1 204 No Content\n\n"
	case "/etag":
		raw = "HTTP/1.1 200 OK\nEtag: \"tag\"\n\n"
	case "/png":
		m := image.NewNRGBA(image.Rect(0, 0, 1, 1))
		img := new(bytes.Buffer)
		png.Encode(img, m)

		raw = fmt.Sprintf("HTTP/1.1 200 OK\nContent-Length: %d\n\n%s", len(img.Bytes()), img.Bytes())
	default:
		raw = "HTTP/1.1 404 Not Found\n\n"
	}

	buf := bufio.NewReader(bytes.NewBufferString(raw))
	return http.ReadResponse(buf, req)
}

func createSwatch(col color.Color, size int) image.Image {
	log.Printf("Creating swatch for %v\n", col)
	bounds := image.Rect(0, 0, size, size)
	img := image.NewNRGBA(bounds)
	draw.Draw(img, img.Bounds(), image.NewUniform(col), img.Bounds().Min, draw.Src)
	return img
}

// cut out the image and return individual channels with image.Image
// no encoding of JPEG
func cut(original image.Image, db *map[string][3]float64, tileSize, x1, y1, x2, y2 int) <-chan image.Image {
	c := make(chan image.Image)
	sp := image.Point{0, 0}
	go func() {
		newimage := image.NewNRGBA(image.Rect(x1, y1, x2, y2))
		for y := y1; y < y2; y = y + tileSize {
			for x := x1; x < x2; x = x + tileSize {
				r, g, b, _ := original.At(x, y).RGBA()
				color := [3]float64{float64(r), float64(g), float64(b)}
				nearest := nearest(color, db)
				file, err := os.Open(nearest)
				if err == nil {
					img, _, err := image.Decode(file)
					if err == nil {
						t := resize(img, tileSize)
						tile := t.SubImage(t.Bounds())
						tileBounds := image.Rect(x, y, x+tileSize, y+tileSize)
						draw.Draw(newimage, tileBounds, tile, sp, draw.Src)
					} else {
						fmt.Println("error in decoding nearest", err, nearest)
					}
				} else {
					fmt.Println("error opening file when creating mosaic:", nearest)
				}
				file.Close()
			}
		}
		c <- newimage.SubImage(newimage.Rect)
	}()

	return c
}

func draw_image(filename string, plot_map map[Key]Point, width int, height int, gradient string) {
	build_gradient(gradient)
	fill_palette()

	bounds := image.Rect(0, 0, width, height)

	b := image.NewNRGBA(bounds)
	draw.Draw(b, bounds, image.NewUniform(color.Black), image.ZP, draw.Src)

	for x := 0; x < width; x += 1 {
		for y := 0; y < height; y += 1 {
			var p = plot_map[Key{x, y}]
			b.Set(p.X, p.Y, get_colour(p.Escape))
		}
	}
	file, err := os.Create(filename)
	if err != nil {
		fmt.Println(err)
	}

	if err = jpeg.Encode(file, b, &jpeg.Options{jpeg.DefaultQuality}); err != nil {
		fmt.Println(err)
	}

	if err = file.Close(); err != nil {
		fmt.Println(err)
	}
}

// AdjustFunc applies the fn function to each pixel of the img image and returns the adjusted image.
//
// Example:
//
// 	dstImage = imaging.AdjustFunc(
// 		srcImage,
// 		func(c color.NRGBA) color.NRGBA {
// 			// shift the red channel by 16
//			r := int(c.R) + 16
//			if r > 255 {
// 				r = 255
// 			}
// 			return color.NRGBA{uint8(r), c.G, c.B, c.A}
// 		}
// 	)
//
func AdjustFunc(img image.Image, fn func(c color.NRGBA) color.NRGBA) *image.NRGBA {
	src := toNRGBA(img)
	width := src.Bounds().Max.X
	height := src.Bounds().Max.Y
	dst := image.NewNRGBA(image.Rect(0, 0, width, height))

	parallel(height, func(partStart, partEnd int) {
		for y := partStart; y < partEnd; y++ {
			for x := 0; x < width; x++ {
				i := y*src.Stride + x*4
				j := y*dst.Stride + x*4

				r := src.Pix[i+0]
				g := src.Pix[i+1]
				b := src.Pix[i+2]
				a := src.Pix[i+3]

				c := fn(color.NRGBA{r, g, b, a})

				dst.Pix[j+0] = c.R
				dst.Pix[j+1] = c.G
				dst.Pix[j+2] = c.B
				dst.Pix[j+3] = c.A
			}
		}
	})

	return dst
}

func (ir *ImageRenderer) RenderToFile(filename string) {
	img := image.NewNRGBA(image.Rect(0, 0, ir.Width, ir.Height))

	for y := 0; y < ir.Height; y++ {
		for x := 0; x < ir.Width; x++ {
			i := y*ir.Width*4 + x*4
			r := uint8(ir.Pixels[i] * 255.0)
			g := uint8(ir.Pixels[i+1] * 255.0)
			b := uint8(ir.Pixels[i+2] * 255.0)
			a := uint8(ir.Pixels[i+3] * 255.0)
			c := color.NRGBA{r, g, b, a}

			img.Set(x, y, c)
		}
	}

	imgWriter, _ := os.Create(filename)
	defer imgWriter.Close()

	var err error
	switch filepath.Ext(filename) {
	case ".png":
		err = png.Encode(imgWriter, img)
	case ".jpg", ".jpeg":
		err = jpeg.Encode(imgWriter, img, &jpeg.Options{Quality: jpeg.DefaultQuality})
	}

	if err != nil {
		fmt.Printf("Error writing out %v: %v", filename, err)
	}
}