Esempio n. 1
0
func nearestGray16(in *image.Gray16, out *image.Gray16, scale float64, coeffs []bool, offset []int, filterLength int) {
	newBounds := out.Bounds()
	maxX := in.Bounds().Dx() - 1

	for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
		row := in.Pix[x*in.Stride:]
		for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
			var gray float32
			var sum float32
			start := offset[y]
			ci := y * filterLength
			for i := 0; i < filterLength; i++ {
				if coeffs[ci+i] {
					xi := start + i
					switch {
					case xi < 0:
						xi = 0
					case xi >= maxX:
						xi = 2 * maxX
					default:
						xi *= 2
					}
					gray += float32(uint16(row[xi+0])<<8 | uint16(row[xi+1]))
					sum++
				}
			}

			offset := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*2
			value := floatToUint16(gray / sum)
			out.Pix[offset+0] = uint8(value >> 8)
			out.Pix[offset+1] = uint8(value)
		}
	}
}
Esempio n. 2
0
func resizeGray16(in *image.Gray16, out *image.Gray16, scale float64, coeffs []int32, offset []int, filterLength int) {
	newBounds := out.Bounds()
	maxX := in.Bounds().Dx() - 1

	for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
		row := in.Pix[x*in.Stride:]
		for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
			var gray int64
			var sum int64
			start := offset[y]
			ci := y * filterLength
			for i := 0; i < filterLength; i++ {
				coeff := coeffs[ci+i]
				if coeff != 0 {
					xi := start + i
					switch {
					case uint(xi) < uint(maxX):
						xi *= 2
					case xi >= maxX:
						xi = 2 * maxX
					default:
						xi = 0
					}
					gray += int64(coeff) * int64(uint16(row[xi+0])<<8|uint16(row[xi+1]))
					sum += int64(coeff)
				}
			}

			offset := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*2
			value := clampUint16(gray / sum)
			out.Pix[offset+0] = uint8(value >> 8)
			out.Pix[offset+1] = uint8(value)
		}
	}
}
Esempio n. 3
0
// Interpolate uint16/pixel images.
func interpolate1x16(src *image.Gray16, dstW, dstH int) image.Image {
	srcRect := src.Bounds()
	srcW := srcRect.Dx()
	srcH := srcRect.Dy()

	ww, hh := uint64(dstW), uint64(dstH)
	dx, dy := uint64(srcW), uint64(srcH)

	n, sum := dx*dy, make([]uint64, dstW*dstH)
	for y := 0; y < srcH; y++ {
		pixOffset := src.PixOffset(0, y)
		for x := 0; x < srcW; x++ {
			// Get the source pixel.
			val64 := uint64(binary.BigEndian.Uint16([]byte(src.Pix[pixOffset+0 : pixOffset+2])))
			pixOffset += 2

			// Spread the source pixel over 1 or more destination rows.
			py := uint64(y) * hh
			for remy := hh; remy > 0; {
				qy := dy - (py % dy)
				if qy > remy {
					qy = remy
				}
				// Spread the source pixel over 1 or more destination columns.
				px := uint64(x) * ww
				index := (py/dy)*ww + (px / dx)
				for remx := ww; remx > 0; {
					qx := dx - (px % dx)
					if qx > remx {
						qx = remx
					}
					qxy := qx * qy
					sum[index] += val64 * qxy
					index++
					px += qx
					remx -= qx
				}
				py += qy
				remy -= qy
			}
		}
	}
	dst := image.NewGray16(image.Rect(0, 0, dstW, dstH))
	index := 0
	for y := 0; y < dstH; y++ {
		pixOffset := dst.PixOffset(0, y)
		for x := 0; x < dstW; x++ {
			binary.BigEndian.PutUint16(dst.Pix[pixOffset+0:pixOffset+2], uint16(sum[index]/n))
			pixOffset += 2
			index++
		}
	}
	return dst
}
Esempio n. 4
0
func resize1x16(src *image.Gray16, dstW, dstH int) image.Image {
	srcRect := src.Bounds()
	srcW := srcRect.Dx()
	srcH := srcRect.Dy()

	dstW64, dstH64 := uint64(dstW), uint64(dstH)
	srcW64, srcH64 := uint64(srcW), uint64(srcH)

	dst := image.NewGray16(image.Rect(0, 0, dstW, dstH))
	var x, y uint64
	dstI := 0
	for y = 0; y < dstH64; y++ {
		srcY := int(y * srcH64 / dstH64)
		for x = 0; x < dstW64; x++ {
			srcX := int(x * srcW64 / dstW64)
			srcI := 2 * (srcY*srcW + srcX)
			copy(dst.Pix[dstI:dstI+2], src.Pix[srcI:srcI+2])
			dstI += 2
		}
	}
	return dst
}