caire/grayscale.go

23 lines
496 B
Go

package caire
import (
"image"
"image/color"
)
// Grayscale converts the image to grayscale mode.
func (c *Carver) Grayscale(src *image.NRGBA) *image.NRGBA {
dx, dy := src.Bounds().Max.X, src.Bounds().Max.Y
dst := image.NewNRGBA(src.Bounds())
for x := 0; x < dx; x++ {
for y := 0; y < dy; y++ {
r, g, b, _ := src.At(x, y).RGBA()
lum := float32(r)*0.299 + float32(g)*0.587 + float32(b)*0.114
pixel := color.Gray{Y: uint8(lum / 256)}
dst.Set(x, y, pixel)
}
}
return dst
}