delete unused blending functions

blendcolor.go

@@ -1,35 +0,0 @@
-package thumbnail
-
-import (
-	"image/color"
-)
-
-func Blend(a, b color.Color) color.Color {
-	switch a.(type) {
-	case color.RGBA:
-		return BlendRGBA(a.(color.RGBA), b.(color.RGBA)) // FIXME there's syntax for this
-
-	case color.YCbCr:
-		return BlendYCbCr(a.(color.YCbCr), b.(color.YCbCr))
-
-	default:
-		return a // ??? unknown color format
-	}
-}
-
-func BlendYCbCr(a, b color.YCbCr) color.YCbCr {
-	return color.YCbCr{
-		Y:  uint8((int(a.Y) + int(b.Y)) / 2),
-		Cb: uint8((int(a.Cb) + int(b.Cb)) / 2),
-		Cr: uint8((int(a.Cr) + int(b.Cr)) / 2),
-	}
-}
-
-func BlendRGBA(a, b color.RGBA) color.RGBA {
-	return color.RGBA{
-		R: uint8((int(a.R) + int(b.R)) / 2),
-		G: uint8((int(a.G) + int(b.G)) / 2),
-		B: uint8((int(a.B) + int(b.B)) / 2),
-		A: uint8((int(a.A) + int(b.A)) / 2),
-	}
-}