/*
Copyright (c) 2012, Jan Schlicht <jan.schlicht@gmail.com>
Permission to use, copy, modify, and/or distribute this software for any purpose
with or without fee is hereby granted, provided that the above copyright notice
and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
THIS SOFTWARE.
*/
package resize
import "image"
// Keep value in [0,255] range.
func clampUint8(in int32) uint8 {
// casting a negative int to an uint will result in an overflown
// large uint. this behavior will be exploited here and in other functions
// to achieve a higher performance.
if uint32(in) < 256 {
return uint8(in)
}
if in > 255 {
return 255
}
return 0
}
// Keep value in [0,65535] range.
func clampUint16(in int64) uint16 {
if uint64(in) < 65536 {
return uint16(in)
}
if in > 65535 {
return 65535
}
return 0
}
func resizeGeneric(in image.Image, out *image.RGBA64, 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++ {
for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
var rgba [4]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 xi < 0:
xi = 0
case xi >= maxX:
xi = maxX
}
r, g, b, a := in.At(xi+in.Bounds().Min.X, x+in.Bounds().Min.Y).RGBA()
rgba[0] += int64(coeff) * int64(r)
rgba[1] += int64(coeff) * int64(g)
rgba[2] += int64(coeff) * int64(b)
rgba[3] += int64(coeff) * int64(a)
sum += int64(coeff)
}
}
offset := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8
value := clampUint16(rgba[0] / sum)
out.Pix[offset+0] = uint8(value >> 8)
out.Pix[offset+1] = uint8(value)
value = clampUint16(rgba[1] / sum)
out.Pix[offset+2] = uint8(value >> 8)
out.Pix[offset+3] = uint8(value)
value = clampUint16(rgba[2] / sum)
out.Pix[offset+4] = uint8(value >> 8)
out.Pix[offset+5] = uint8(value)
value = clampUint16(rgba[3] / sum)
out.Pix[offset+6] = uint8(value >> 8)
out.Pix[offset+7] = uint8(value)
}
}
}
func resizeRGBA(in *image.RGBA, out *image.RGBA, scale float64, coeffs []int16, 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 rgba [4]int32
var sum int32
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 *= 4
case xi >= maxX:
xi = 4 * maxX
default:
xi = 0
}
rgba[0] += int32(coeff) * int32(row[xi+0])
rgba[1] += int32(coeff) * int32(row[xi+1])
rgba[2] += int32(coeff) * int32(row[xi+2])
rgba[3] += int32(coeff) * int32(row[xi+3])
sum += int32(coeff)
}
}
xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*4
out.Pix[xo+0] = clampUint8(rgba[0] / sum)
out.Pix[xo+1] = clampUint8(rgba[1] / sum)
out.Pix[xo+2] = clampUint8(rgba[2] / sum)
out.Pix[xo+3] = clampUint8(rgba[3] / sum)
}
}
}
func resizeNRGBA(in *image.NRGBA, out *image.RGBA, scale float64, coeffs []int16, 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 rgba [4]int32
var sum int32
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 *= 4
case xi >= maxX:
xi = 4 * maxX
default:
xi = 0
}
// Forward alpha-premultiplication
a := int32(row[xi+3])
r := int32(row[xi+0]) * a
r /= 0xff
g := int32(row[xi+1]) * a
g /= 0xff
b := int32(row[xi+2]) * a
b /= 0xff
rgba[0] += int32(coeff) * r
rgba[1] += int32(coeff) * g
rgba[2] += int32(coeff) * b
rgba[3] += int32(coeff) * a
sum += int32(coeff)
}
}
xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*4
out.Pix[xo+0] = clampUint8(rgba[0] / sum)
out.Pix[xo+1] = clampUint8(rgba[1] / sum)
out.Pix[xo+2] = clampUint8(rgba[2] / sum)
out.Pix[xo+3] = clampUint8(rgba[3] / sum)
}
}
}
func resizeRGBA64(in *image.RGBA64, out *image.RGBA64, 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 rgba [4]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 *= 8
case xi >= maxX:
xi = 8 * maxX
default:
xi = 0
}
rgba[0] += int64(coeff) * (int64(row[xi+0])<<8 | int64(row[xi+1]))
rgba[1] += int64(coeff) * (int64(row[xi+2])<<8 | int64(row[xi+3]))
rgba[2] += int64(coeff) * (int64(row[xi+4])<<8 | int64(row[xi+5]))
rgba[3] += int64(coeff) * (int64(row[xi+6])<<8 | int64(row[xi+7]))
sum += int64(coeff)
}
}
xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8
value := clampUint16(rgba[0] / sum)
out.Pix[xo+0] = uint8(value >> 8)
out.Pix[xo+1] = uint8(value)
value = clampUint16(rgba[1] / sum)
out.Pix[xo+2] = uint8(value >> 8)
out.Pix[xo+3] = uint8(value)
value = clampUint16(rgba[2] / sum)
out.Pix[xo+4] = uint8(value >> 8)
out.Pix[xo+5] = uint8(value)
value = clampUint16(rgba[3] / sum)
out.Pix[xo+6] = uint8(value >> 8)
out.Pix[xo+7] = uint8(value)
}
}
}
func resizeNRGBA64(in *image.NRGBA64, out *image.RGBA64, 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 rgba [4]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 *= 8
case xi >= maxX:
xi = 8 * maxX
default:
xi = 0
}
// Forward alpha-premultiplication
a := int64(uint16(row[xi+6])<<8 | uint16(row[xi+7]))
r := int64(uint16(row[xi+0])<<8|uint16(row[xi+1])) * a
r /= 0xffff
g := int64(uint16(row[xi+2])<<8|uint16(row[xi+3])) * a
g /= 0xffff
b := int64(uint16(row[xi+4])<<8|uint16(row[xi+5])) * a
b /= 0xffff
rgba[0] += int64(coeff) * r
rgba[1] += int64(coeff) * g
rgba[2] += int64(coeff) * b
rgba[3] += int64(coeff) * a
sum += int64(coeff)
}
}
xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8
value := clampUint16(rgba[0] / sum)
out.Pix[xo+0] = uint8(value >> 8)
out.Pix[xo+1] = uint8(value)
value = clampUint16(rgba[1] / sum)
out.Pix[xo+2] = uint8(value >> 8)
out.Pix[xo+3] = uint8(value)
value = clampUint16(rgba[2] / sum)
out.Pix[xo+4] = uint8(value >> 8)
out.Pix[xo+5] = uint8(value)
value = clampUint16(rgba[3] / sum)
out.Pix[xo+6] = uint8(value >> 8)
out.Pix[xo+7] = uint8(value)
}
}
}
func resizeGray(in *image.Gray, out *image.Gray, scale float64, coeffs []int16, 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-newBounds.Min.X)*in.Stride:]
for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
var gray int32
var sum int32
start := offset[y]
ci := y * filterLength
for i := 0; i < filterLength; i++ {
coeff := coeffs[ci+i]
if coeff != 0 {
xi := start + i
switch {
case xi < 0:
xi = 0
case xi >= maxX:
xi = maxX
}
gray += int32(coeff) * int32(row[xi])
sum += int32(coeff)
}
}
offset := (y-newBounds.Min.Y)*out.Stride + (x - newBounds.Min.X)
out.Pix[offset] = clampUint8(gray / sum)
}
}
}
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)
}
}
}
func resizeYCbCr(in *ycc, out *ycc, scale float64, coeffs []int16, 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 p [3]int32
var sum int32
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 *= 3
case xi >= maxX:
xi = 3 * maxX
default:
xi = 0
}
p[0] += int32(coeff) * int32(row[xi+0])
p[1] += int32(coeff) * int32(row[xi+1])
p[2] += int32(coeff) * int32(row[xi+2])
sum += int32(coeff)
}
}
xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*3
out.Pix[xo+0] = clampUint8(p[0] / sum)
out.Pix[xo+1] = clampUint8(p[1] / sum)
out.Pix[xo+2] = clampUint8(p[2] / sum)
}
}
}
func nearestYCbCr(in *ycc, out *ycc, 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 p [3]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 uint(xi) < uint(maxX):
xi *= 3
case xi >= maxX:
xi = 3 * maxX
default:
xi = 0
}
p[0] += float32(row[xi+0])
p[1] += float32(row[xi+1])
p[2] += float32(row[xi+2])
sum++
}
}
xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*3
out.Pix[xo+0] = floatToUint8(p[0] / sum)
out.Pix[xo+1] = floatToUint8(p[1] / sum)
out.Pix[xo+2] = floatToUint8(p[2] / sum)
}
}
}