polygon

polygon-img

##use golang to crop an image to polygon

Notice:

the point area must be clockwise

Hot to get

go get github.com/dangwan/polygon

test case

func main(){
    f, _ := os.Open("garden.jpeg")
    img, _, _ := image.Decode(f)
        c := polygon.Polygon{
        Width:  img.Bounds().Dx(),
        Height: img.Bounds().Dy(),
        Area: []polygon.Point{
            {200, 0},
            {600, 300},
            {100, 350},
            {0, 100},
        },
    }
    rgbaImg, _ := polygon.ClipForPolygon(&c, img)
}

result show

before

after crop: