40 lines
954 B
Go
40 lines
954 B
Go
package loader
|
||
|
||
import (
|
||
"image"
|
||
"image/color"
|
||
)
|
||
|
||
// ExtractAlpha 将白色/浅灰背景转换为透明，保留非白色像素
|
||
// 用于处理 AI 生成的装饰图（MiniMax 可能不输出透明 PNG）
|
||
func ExtractAlpha(img image.Image) *image.NRGBA {
|
||
bounds := img.Bounds()
|
||
result := image.NewNRGBA(bounds)
|
||
|
||
for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
|
||
for x := bounds.Min.X; x < bounds.Max.X; x++ {
|
||
r, g, b, a := img.At(x, y).RGBA()
|
||
|
||
// 将 uint32 (0-65535) 归一化到 0-1
|
||
rf := float64(r) / 65535.0
|
||
gf := float64(g) / 65535.0
|
||
bf := float64(b) / 65535.0
|
||
|
||
// 亮度 > 90% 的视为白色/浅灰背景，设为透明
|
||
luminance := (rf + gf + bf) / 3.0
|
||
if luminance > 0.90 {
|
||
result.SetNRGBA(x, y, color.NRGBA{R: 0, G: 0, B: 0, A: 0})
|
||
} else {
|
||
result.SetNRGBA(x, y, color.NRGBA{
|
||
R: uint8(r >> 8),
|
||
G: uint8(g >> 8),
|
||
B: uint8(b >> 8),
|
||
A: uint8(a >> 8),
|
||
})
|
||
}
|
||
}
|
||
}
|
||
|
||
return result
|
||
}
|