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Using golang to mark the picture
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| package main | |
| import ( | |
| "bytes" | |
| "fmt" | |
| "strings" | |
| "io/ioutil" | |
| "os" | |
| "path" | |
| "math" | |
| "math/rand" | |
| "time" | |
| "image" | |
| "image/color" | |
| "image/draw" | |
| "image/jpeg" | |
| "image/png" | |
| "github.com/gonum/plot/vg" | |
| "github.com/gonum/plot/vg/vgimg" | |
| ) | |
| func init() { | |
| rand.Seed(time.Now().UnixNano()) | |
| } | |
| // WaterMark for adding a watermark on the image | |
| func WaterMark(img image.Image, markText string) (image.Image, error) { | |
| // image's length to canvas's length | |
| bounds := img.Bounds() | |
| w := vg.Length(bounds.Max.X) * vg.Inch / vgimg.DefaultDPI | |
| h := vg.Length(bounds.Max.Y) * vg.Inch / vgimg.DefaultDPI | |
| diagonal := vg.Length(math.Sqrt(float64(w*w + h*h))) | |
| // create a canvas, which width and height are diagonal | |
| c := vgimg.New(diagonal, diagonal) | |
| // draw image on the center of canvas | |
| rect := vg.Rectangle{} | |
| rect.Min.X = diagonal/2 - w/2 | |
| rect.Min.Y = diagonal/2 - h/2 | |
| rect.Max.X = diagonal/2 + w/2 | |
| rect.Max.Y = diagonal/2 + h/2 | |
| c.DrawImage(rect, img) | |
| // make a fontStyle, which width is vg.Inch * 0.7 | |
| fontStyle, _ := vg.MakeFont("Courier", vg.Inch*0.7) | |
| // repeat the markText | |
| markTextWidth := fontStyle.Width(markText) | |
| unitText := markText | |
| for markTextWidth <= diagonal { | |
| markText += " " + unitText | |
| markTextWidth = fontStyle.Width(markText) | |
| } | |
| // set the color of markText | |
| c.SetColor(color.RGBA{0, 0, 0, 122}) | |
| // set a random angle between 0 and π/2 | |
| θ := math.Pi * rand.Float64() / 2 | |
| c.Rotate(θ) | |
| // set the lineHeight and add the markText | |
| lineHeight := fontStyle.Extents().Height * 1 | |
| for offset := -2 * diagonal; offset < 2*diagonal; offset += lineHeight { | |
| c.FillString(fontStyle, vg.Point{X: 0, Y: offset}, markText) | |
| } | |
| // canvas writeto jpeg | |
| // canvas.img is private | |
| // so use a buffer to transfer | |
| jc := vgimg.PngCanvas{Canvas: c} | |
| buff := new(bytes.Buffer) | |
| jc.WriteTo(buff) | |
| img, _, err := image.Decode(buff) | |
| if err != nil { | |
| return nil, err | |
| } | |
| // get the center point of the image | |
| ctp := int(diagonal * vgimg.DefaultDPI / vg.Inch / 2) | |
| // cutout the marked image | |
| size := bounds.Size() | |
| bounds = image.Rect(ctp-size.X/2, ctp-size.Y/2, ctp+size.X/2, ctp+size.Y/2) | |
| rv := image.NewRGBA(bounds) | |
| draw.Draw(rv, bounds, img, bounds.Min, draw.Src) | |
| return rv, nil | |
| } | |
| // MarkingPicture for marking picture with text | |
| func MarkingPicture(filepath, text string) (image.Image, error) { | |
| f, err := os.Open(filepath) | |
| if err != nil { | |
| return nil, err | |
| } | |
| defer f.Close() | |
| img, _, err := image.Decode(f) | |
| if err != nil { | |
| return nil, err | |
| } | |
| img, err = WaterMark(img, text) | |
| if err != nil { | |
| return nil, err | |
| } | |
| return img, nil | |
| } | |
| func writeTo(img image.Image, ext string) (rv *bytes.Buffer, err error) { | |
| ext = strings.ToLower(ext) | |
| rv = new(bytes.Buffer) | |
| switch ext { | |
| case ".jpg", ".jpeg": | |
| err = jpeg.Encode(rv, img, &jpeg.Options{Quality: 100}) | |
| case ".png": | |
| err = png.Encode(rv, img) | |
| } | |
| return rv, err | |
| } | |
| func main() { | |
| if len(os.Args) < 3 { | |
| panic(fmt.Errorf("Please using like this:$ %s [file or directory] [text]", os.Args[0])) | |
| } | |
| target := os.Args[1] | |
| text := os.Args[2] | |
| if stat, err := os.Stat(target); err == nil && stat.IsDir() { | |
| files, _ := ioutil.ReadDir(target) | |
| for _, fn := range files { | |
| img, err := MarkingPicture(path.Join(target, fn.Name()), text) | |
| if err != nil { | |
| continue | |
| } | |
| ext := path.Ext(fn.Name()) | |
| base := strings.Split(fn.Name(), ".")[0] + "_marked" | |
| f, err := os.Create(base + ext) | |
| if err != nil { | |
| panic(err) | |
| } | |
| buff, err := writeTo(img, ext) | |
| if err != nil { | |
| panic(err) | |
| } | |
| if _, err = buff.WriteTo(f); err != nil { | |
| panic(err) | |
| } | |
| } | |
| } else { | |
| img, err := MarkingPicture(target, text) | |
| if err != nil { | |
| panic(err) | |
| } | |
| ext := path.Ext(target) | |
| base := strings.Split(path.Base(target), ".")[0] + "_marked" | |
| f, err := os.Create(base + ext) | |
| if err != nil { | |
| panic(err) | |
| } | |
| buff, err := writeTo(img, ext) | |
| if err != nil { | |
| panic(err) | |
| } | |
| if _, err = buff.WriteTo(f); err != nil { | |
| panic(err) | |
| } | |
| } | |
| } |
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亲测有效
"gonum.org/v1/plot/vg" 用v0.8.1
增加支持中文字体，字体文件为PingFang SC Medium.ttf