diff options
Diffstat (limited to 'vendor/github.com/disintegration/imaging/scanner.go')
| -rw-r--r-- | vendor/github.com/disintegration/imaging/scanner.go | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/vendor/github.com/disintegration/imaging/scanner.go b/vendor/github.com/disintegration/imaging/scanner.go new file mode 100644 index 00000000..37d92cef --- /dev/null +++ b/vendor/github.com/disintegration/imaging/scanner.go @@ -0,0 +1,285 @@ +package imaging + +import ( + "image" + "image/color" +) + +type scanner struct { + image image.Image + w, h int + palette []color.NRGBA +} + +func newScanner(img image.Image) *scanner { + s := &scanner{ + image: img, + w: img.Bounds().Dx(), + h: img.Bounds().Dy(), + } + if img, ok := img.(*image.Paletted); ok { + s.palette = make([]color.NRGBA, len(img.Palette)) + for i := 0; i < len(img.Palette); i++ { + s.palette[i] = color.NRGBAModel.Convert(img.Palette[i]).(color.NRGBA) + } + } + return s +} + +// scan scans the given rectangular region of the image into dst. +func (s *scanner) scan(x1, y1, x2, y2 int, dst []uint8) { + switch img := s.image.(type) { + case *image.NRGBA: + size := (x2 - x1) * 4 + j := 0 + i := y1*img.Stride + x1*4 + if size == 4 { + for y := y1; y < y2; y++ { + d := dst[j : j+4 : j+4] + s := img.Pix[i : i+4 : i+4] + d[0] = s[0] + d[1] = s[1] + d[2] = s[2] + d[3] = s[3] + j += size + i += img.Stride + } + } else { + for y := y1; y < y2; y++ { + copy(dst[j:j+size], img.Pix[i:i+size]) + j += size + i += img.Stride + } + } + + case *image.NRGBA64: + j := 0 + for y := y1; y < y2; y++ { + i := y*img.Stride + x1*8 + for x := x1; x < x2; x++ { + s := img.Pix[i : i+8 : i+8] + d := dst[j : j+4 : j+4] + d[0] = s[0] + d[1] = s[2] + d[2] = s[4] + d[3] = s[6] + j += 4 + i += 8 + } + } + + case *image.RGBA: + j := 0 + for y := y1; y < y2; y++ { + i := y*img.Stride + x1*4 + for x := x1; x < x2; x++ { + d := dst[j : j+4 : j+4] + a := img.Pix[i+3] + switch a { + case 0: + d[0] = 0 + d[1] = 0 + d[2] = 0 + d[3] = a + case 0xff: + s := img.Pix[i : i+4 : i+4] + d[0] = s[0] + d[1] = s[1] + d[2] = s[2] + d[3] = a + default: + s := img.Pix[i : i+4 : i+4] + r16 := uint16(s[0]) + g16 := uint16(s[1]) + b16 := uint16(s[2]) + a16 := uint16(a) + d[0] = uint8(r16 * 0xff / a16) + d[1] = uint8(g16 * 0xff / a16) + d[2] = uint8(b16 * 0xff / a16) + d[3] = a + } + j += 4 + i += 4 + } + } + + case *image.RGBA64: + j := 0 + for y := y1; y < y2; y++ { + i := y*img.Stride + x1*8 + for x := x1; x < x2; x++ { + s := img.Pix[i : i+8 : i+8] + d := dst[j : j+4 : j+4] + a := s[6] + switch a { + case 0: + d[0] = 0 + d[1] = 0 + d[2] = 0 + case 0xff: + d[0] = s[0] + d[1] = s[2] + d[2] = s[4] + default: + r32 := uint32(s[0])<<8 | uint32(s[1]) + g32 := uint32(s[2])<<8 | uint32(s[3]) + b32 := uint32(s[4])<<8 | uint32(s[5]) + a32 := uint32(s[6])<<8 | uint32(s[7]) + d[0] = uint8((r32 * 0xffff / a32) >> 8) + d[1] = uint8((g32 * 0xffff / a32) >> 8) + d[2] = uint8((b32 * 0xffff / a32) >> 8) + } + d[3] = a + j += 4 + i += 8 + } + } + + case *image.Gray: + j := 0 + for y := y1; y < y2; y++ { + i := y*img.Stride + x1 + for x := x1; x < x2; x++ { + c := img.Pix[i] + d := dst[j : j+4 : j+4] + d[0] = c + d[1] = c + d[2] = c + d[3] = 0xff + j += 4 + i++ + } + } + + case *image.Gray16: + j := 0 + for y := y1; y < y2; y++ { + i := y*img.Stride + x1*2 + for x := x1; x < x2; x++ { + c := img.Pix[i] + d := dst[j : j+4 : j+4] + d[0] = c + d[1] = c + d[2] = c + d[3] = 0xff + j += 4 + i += 2 + } + } + + case *image.YCbCr: + j := 0 + x1 += img.Rect.Min.X + x2 += img.Rect.Min.X + y1 += img.Rect.Min.Y + y2 += img.Rect.Min.Y + + hy := img.Rect.Min.Y / 2 + hx := img.Rect.Min.X / 2 + for y := y1; y < y2; y++ { + iy := (y-img.Rect.Min.Y)*img.YStride + (x1 - img.Rect.Min.X) + + var yBase int + switch img.SubsampleRatio { + case image.YCbCrSubsampleRatio444, image.YCbCrSubsampleRatio422: + yBase = (y - img.Rect.Min.Y) * img.CStride + case image.YCbCrSubsampleRatio420, image.YCbCrSubsampleRatio440: + yBase = (y/2 - hy) * img.CStride + } + + for x := x1; x < x2; x++ { + var ic int + switch img.SubsampleRatio { + case image.YCbCrSubsampleRatio444, image.YCbCrSubsampleRatio440: + ic = yBase + (x - img.Rect.Min.X) + case image.YCbCrSubsampleRatio422, image.YCbCrSubsampleRatio420: + ic = yBase + (x/2 - hx) + default: + ic = img.COffset(x, y) + } + + yy1 := int32(img.Y[iy]) * 0x10101 + cb1 := int32(img.Cb[ic]) - 128 + cr1 := int32(img.Cr[ic]) - 128 + + r := yy1 + 91881*cr1 + if uint32(r)&0xff000000 == 0 { + r >>= 16 + } else { + r = ^(r >> 31) + } + + g := yy1 - 22554*cb1 - 46802*cr1 + if uint32(g)&0xff000000 == 0 { + g >>= 16 + } else { + g = ^(g >> 31) + } + + b := yy1 + 116130*cb1 + if uint32(b)&0xff000000 == 0 { + b >>= 16 + } else { + b = ^(b >> 31) + } + + d := dst[j : j+4 : j+4] + d[0] = uint8(r) + d[1] = uint8(g) + d[2] = uint8(b) + d[3] = 0xff + + iy++ + j += 4 + } + } + + case *image.Paletted: + j := 0 + for y := y1; y < y2; y++ { + i := y*img.Stride + x1 + for x := x1; x < x2; x++ { + c := s.palette[img.Pix[i]] + d := dst[j : j+4 : j+4] + d[0] = c.R + d[1] = c.G + d[2] = c.B + d[3] = c.A + j += 4 + i++ + } + } + + default: + j := 0 + b := s.image.Bounds() + x1 += b.Min.X + x2 += b.Min.X + y1 += b.Min.Y + y2 += b.Min.Y + for y := y1; y < y2; y++ { + for x := x1; x < x2; x++ { + r16, g16, b16, a16 := s.image.At(x, y).RGBA() + d := dst[j : j+4 : j+4] + switch a16 { + case 0xffff: + d[0] = uint8(r16 >> 8) + d[1] = uint8(g16 >> 8) + d[2] = uint8(b16 >> 8) + d[3] = 0xff + case 0: + d[0] = 0 + d[1] = 0 + d[2] = 0 + d[3] = 0 + default: + d[0] = uint8(((r16 * 0xffff) / a16) >> 8) + d[1] = uint8(((g16 * 0xffff) / a16) >> 8) + d[2] = uint8(((b16 * 0xffff) / a16) >> 8) + d[3] = uint8(a16 >> 8) + } + j += 4 + } + } + } +} |