30 lines
602 B
Go
30 lines
602 B
Go
|
package main
|
||
|
|
|
||
|
|
import (
|
||
|
|
"image"
|
||
|
|
"image/color"
|
||
|
|
)
|
||
|
|
|
||
|
|
func convertToGray(path string) error {
|
||
|
|
src, err := decodeImage(path)
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
bounds := src.Bounds()
|
||
|
|
dst := image.NewRGBA(bounds)
|
||
|
|
for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
|
||
|
|
for x := bounds.Min.X; x < bounds.Max.X; x++ {
|
||
|
|
c := src.At(x, y)
|
||
|
|
rgba := color.NRGBAModel.Convert(c).(color.NRGBA)
|
||
|
|
if rgba.A > 0 {
|
||
|
|
gray := color.GrayModel.Convert(c).(color.Gray)
|
||
|
|
rgba.R, rgba.G, rgba.B = gray.Y, gray.Y, gray.Y
|
||
|
|
dst.Set(x, y, rgba)
|
||
|
|
} else {
|
||
|
|
dst.Set(x, y, c)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return encodePNG(path, dst)
|
||
|
|
}
|