package pigo import ( "image" "image/color" "testing" ) const ImgWidth = 10 const ImgHeight = 10 func TestGrayscale(t *testing.T) { img := image.NewRGBA(image.Rect(0, 0, ImgWidth, ImgHeight)) for i := 0; i < img.Bounds().Dx(); i++ { for j := 0; j < img.Bounds().Dy(); j++ { img.Set(i, j, color.RGBA{177, 177, 177, 255}) } } for i := 0; i < img.Bounds().Dx(); i++ { for j := 0; j < img.Bounds().Dy(); j++ { r, g, b, _ := img.At(i, j).RGBA() r = r >> 8 g = g >> 8 b = b >> 8 if r != g || r != b || g != b { t.Errorf("R, G, B value expected to be equal. Got %v, %v, %v", r, g, b) } } } }