624 lines
14 KiB
Go
624 lines
14 KiB
Go
// GoToSocial
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// Copyright (C) GoToSocial Authors admin@gotosocial.org
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// SPDX-License-Identifier: AGPL-3.0-or-later
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Affero General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Affero General Public License for more details.
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//
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// You should have received a copy of the GNU Affero General Public License
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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package media
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import (
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"image"
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"image/color"
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"math"
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)
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// NOTE:
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// the following code is borrowed from
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// github.com/disintegration/imaging
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// and collapses in some places for our
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// particular usecases and with parallel()
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// function (spans work across goroutines)
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// removed, instead working synchronously.
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//
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// at gotosocial we take particular
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// care about where we spawn goroutines
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// to ensure we're in control of the
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// amount of concurrency in relation
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// to the amount configured by user.
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// resizeDownLinear resizes image to given width x height using linear resampling.
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// This is specifically optimized for resizing down (i.e. smaller), else is noop.
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func resizeDownLinear(img image.Image, width, height int) image.Image {
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srcW, srcH := img.Bounds().Dx(), img.Bounds().Dy()
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if srcW <= 0 || srcH <= 0 ||
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width < 0 || height < 0 {
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return &image.NRGBA{}
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}
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if width == 0 {
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// If no width is given, use aspect preserving width.
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tmp := float64(height) * float64(srcW) / float64(srcH)
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width = int(math.Max(1.0, math.Floor(tmp+0.5)))
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}
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if height == 0 {
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// If no height is given, use aspect preserving height.
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tmp := float64(width) * float64(srcH) / float64(srcW)
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height = int(math.Max(1.0, math.Floor(tmp+0.5)))
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}
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if width < srcW {
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// Width is smaller, resize horizontally.
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img = resizeHorizontalLinear(img, width)
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}
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if height < srcH {
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// Height is smaller, resize vertically.
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img = resizeVerticalLinear(img, height)
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}
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return img
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}
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// flipH flips the image horizontally (left to right).
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func flipH(img image.Image) image.Image {
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src := newScanner(img)
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dstW := src.w
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dstH := src.h
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rowSize := dstW * 4
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dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
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for y := 0; y < dstH; y++ {
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i := y * dst.Stride
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srcY := y
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src.scan(0, srcY, src.w, srcY+1, dst.Pix[i:i+rowSize])
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reverse(dst.Pix[i : i+rowSize])
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}
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return dst
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}
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// flipV flips the image vertically (from top to bottom).
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func flipV(img image.Image) image.Image {
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src := newScanner(img)
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dstW := src.w
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dstH := src.h
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rowSize := dstW * 4
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dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
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for y := 0; y < dstH; y++ {
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i := y * dst.Stride
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srcY := dstH - y - 1
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src.scan(0, srcY, src.w, srcY+1, dst.Pix[i:i+rowSize])
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}
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return dst
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}
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// rotate90 rotates the image 90 counter-clockwise.
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func rotate90(img image.Image) image.Image {
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src := newScanner(img)
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dstW := src.h
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dstH := src.w
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rowSize := dstW * 4
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dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
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for y := 0; y < dstH; y++ {
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i := y * dst.Stride
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srcX := dstH - y - 1
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src.scan(srcX, 0, srcX+1, src.h, dst.Pix[i:i+rowSize])
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}
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return dst
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}
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// rotate180 rotates the image 180 counter-clockwise.
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func rotate180(img image.Image) image.Image {
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src := newScanner(img)
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dstW := src.w
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dstH := src.h
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rowSize := dstW * 4
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dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
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for y := 0; y < dstH; y++ {
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i := y * dst.Stride
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srcY := dstH - y - 1
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src.scan(0, srcY, src.w, srcY+1, dst.Pix[i:i+rowSize])
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reverse(dst.Pix[i : i+rowSize])
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}
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return dst
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}
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// rotate270 rotates the image 270 counter-clockwise.
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func rotate270(img image.Image) image.Image {
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src := newScanner(img)
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dstW := src.h
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dstH := src.w
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rowSize := dstW * 4
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dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
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for y := 0; y < dstH; y++ {
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i := y * dst.Stride
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srcX := y
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src.scan(srcX, 0, srcX+1, src.h, dst.Pix[i:i+rowSize])
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reverse(dst.Pix[i : i+rowSize])
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}
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return dst
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}
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// transpose flips the image horizontally and rotates 90 counter-clockwise.
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func transpose(img image.Image) image.Image {
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src := newScanner(img)
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dstW := src.h
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dstH := src.w
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rowSize := dstW * 4
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dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
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for y := 0; y < dstH; y++ {
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i := y * dst.Stride
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srcX := y
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src.scan(srcX, 0, srcX+1, src.h, dst.Pix[i:i+rowSize])
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}
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return dst
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}
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// transverse flips the image vertically and rotates 90 counter-clockwise.
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func transverse(img image.Image) image.Image {
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src := newScanner(img)
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dstW := src.h
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dstH := src.w
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rowSize := dstW * 4
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dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
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for y := 0; y < dstH; y++ {
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i := y * dst.Stride
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srcX := dstH - y - 1
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src.scan(srcX, 0, srcX+1, src.h, dst.Pix[i:i+rowSize])
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reverse(dst.Pix[i : i+rowSize])
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}
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return dst
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}
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// resizeHorizontalLinear resizes image to given width using linear resampling.
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func resizeHorizontalLinear(img image.Image, dstWidth int) image.Image {
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src := newScanner(img)
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dst := image.NewRGBA(image.Rect(0, 0, dstWidth, src.h))
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weights := precomputeWeightsLinear(dstWidth, src.w)
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scanLine := make([]uint8, src.w*4)
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for y := 0; y < src.h; y++ {
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src.scan(0, y, src.w, y+1, scanLine)
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j0 := y * dst.Stride
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for x := range weights {
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var r, g, b, a float64
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for _, w := range weights[x] {
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i := w.index * 4
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s := scanLine[i : i+4 : i+4]
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aw := float64(s[3]) * w.weight
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r += float64(s[0]) * aw
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g += float64(s[1]) * aw
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b += float64(s[2]) * aw
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a += aw
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}
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if a != 0 {
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aInv := 1 / a
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j := j0 + x*4
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d := dst.Pix[j : j+4 : j+4]
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d[0] = clampFloat(r * aInv)
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d[1] = clampFloat(g * aInv)
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d[2] = clampFloat(b * aInv)
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d[3] = clampFloat(a)
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}
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}
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}
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return dst
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}
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// resizeVerticalLinear resizes image to given height using linear resampling.
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func resizeVerticalLinear(img image.Image, height int) image.Image {
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src := newScanner(img)
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dst := image.NewNRGBA(image.Rect(0, 0, src.w, height))
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weights := precomputeWeightsLinear(height, src.h)
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scanLine := make([]uint8, src.h*4)
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for x := 0; x < src.w; x++ {
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src.scan(x, 0, x+1, src.h, scanLine)
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for y := range weights {
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var r, g, b, a float64
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for _, w := range weights[y] {
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i := w.index * 4
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s := scanLine[i : i+4 : i+4]
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aw := float64(s[3]) * w.weight
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r += float64(s[0]) * aw
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g += float64(s[1]) * aw
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b += float64(s[2]) * aw
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a += aw
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}
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if a != 0 {
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aInv := 1 / a
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j := y*dst.Stride + x*4
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d := dst.Pix[j : j+4 : j+4]
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d[0] = clampFloat(r * aInv)
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d[1] = clampFloat(g * aInv)
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d[2] = clampFloat(b * aInv)
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d[3] = clampFloat(a)
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}
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}
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}
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return dst
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}
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type indexWeight struct {
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index int
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weight float64
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}
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func precomputeWeightsLinear(dstSize, srcSize int) [][]indexWeight {
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du := float64(srcSize) / float64(dstSize)
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scale := du
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if scale < 1.0 {
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scale = 1.0
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}
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ru := math.Ceil(scale)
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out := make([][]indexWeight, dstSize)
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tmp := make([]indexWeight, 0, dstSize*int(ru+2)*2)
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for v := 0; v < dstSize; v++ {
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fu := (float64(v)+0.5)*du - 0.5
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begin := int(math.Ceil(fu - ru))
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if begin < 0 {
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begin = 0
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}
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end := int(math.Floor(fu + ru))
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if end > srcSize-1 {
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end = srcSize - 1
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}
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var sum float64
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for u := begin; u <= end; u++ {
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w := resampleLinear((float64(u) - fu) / scale)
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if w != 0 {
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sum += w
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tmp = append(tmp, indexWeight{index: u, weight: w})
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}
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}
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if sum != 0 {
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for i := range tmp {
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tmp[i].weight /= sum
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}
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}
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out[v] = tmp
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tmp = tmp[len(tmp):]
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}
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return out
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}
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// resampleLinear is the resample kernel func for linear filtering.
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func resampleLinear(x float64) float64 {
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x = math.Abs(x)
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if x < 1.0 {
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return 1.0 - x
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}
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return 0
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}
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// scanner wraps an image.Image for
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// easier size access and image type
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// agnostic access to data at coords.
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type scanner struct {
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image image.Image
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w, h int
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palette []color.NRGBA
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}
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// newScanner wraps an image.Image in scanner{} type.
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func newScanner(img image.Image) *scanner {
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b := img.Bounds()
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s := &scanner{
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image: img,
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w: b.Dx(),
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h: b.Dy(),
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}
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if img, ok := img.(*image.Paletted); ok {
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s.palette = make([]color.NRGBA, len(img.Palette))
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for i := 0; i < len(img.Palette); i++ {
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s.palette[i] = color.NRGBAModel.Convert(img.Palette[i]).(color.NRGBA)
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}
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}
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return s
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}
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// scan scans the given rectangular region of the image into dst.
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func (s *scanner) scan(x1, y1, x2, y2 int, dst []uint8) {
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switch img := s.image.(type) {
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case *image.NRGBA:
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size := (x2 - x1) * 4
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j := 0
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i := y1*img.Stride + x1*4
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if size == 4 {
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for y := y1; y < y2; y++ {
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d := dst[j : j+4 : j+4]
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s := img.Pix[i : i+4 : i+4]
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d[0] = s[0]
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d[1] = s[1]
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d[2] = s[2]
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d[3] = s[3]
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j += size
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i += img.Stride
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}
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} else {
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for y := y1; y < y2; y++ {
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copy(dst[j:j+size], img.Pix[i:i+size])
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j += size
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i += img.Stride
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}
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}
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case *image.NRGBA64:
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j := 0
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for y := y1; y < y2; y++ {
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i := y*img.Stride + x1*8
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for x := x1; x < x2; x++ {
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s := img.Pix[i : i+8 : i+8]
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d := dst[j : j+4 : j+4]
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d[0] = s[0]
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d[1] = s[2]
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d[2] = s[4]
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d[3] = s[6]
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j += 4
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i += 8
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}
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}
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case *image.RGBA:
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j := 0
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for y := y1; y < y2; y++ {
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i := y*img.Stride + x1*4
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for x := x1; x < x2; x++ {
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d := dst[j : j+4 : j+4]
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a := img.Pix[i+3]
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switch a {
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case 0:
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d[0] = 0
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d[1] = 0
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d[2] = 0
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d[3] = a
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case 0xff:
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s := img.Pix[i : i+4 : i+4]
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d[0] = s[0]
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d[1] = s[1]
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d[2] = s[2]
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d[3] = a
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default:
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s := img.Pix[i : i+4 : i+4]
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r16 := uint16(s[0])
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g16 := uint16(s[1])
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b16 := uint16(s[2])
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a16 := uint16(a)
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d[0] = uint8(r16 * 0xff / a16)
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d[1] = uint8(g16 * 0xff / a16)
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d[2] = uint8(b16 * 0xff / a16)
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d[3] = a
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}
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j += 4
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i += 4
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}
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}
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case *image.RGBA64:
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j := 0
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for y := y1; y < y2; y++ {
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i := y*img.Stride + x1*8
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for x := x1; x < x2; x++ {
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s := img.Pix[i : i+8 : i+8]
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d := dst[j : j+4 : j+4]
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a := s[6]
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switch a {
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case 0:
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d[0] = 0
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d[1] = 0
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d[2] = 0
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case 0xff:
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d[0] = s[0]
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d[1] = s[2]
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d[2] = s[4]
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default:
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r32 := uint32(s[0])<<8 | uint32(s[1])
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g32 := uint32(s[2])<<8 | uint32(s[3])
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b32 := uint32(s[4])<<8 | uint32(s[5])
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a32 := uint32(s[6])<<8 | uint32(s[7])
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d[0] = uint8((r32 * 0xffff / a32) >> 8)
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d[1] = uint8((g32 * 0xffff / a32) >> 8)
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d[2] = uint8((b32 * 0xffff / a32) >> 8)
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}
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d[3] = a
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j += 4
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i += 8
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}
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}
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case *image.Gray:
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j := 0
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for y := y1; y < y2; y++ {
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i := y*img.Stride + x1
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for x := x1; x < x2; x++ {
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c := img.Pix[i]
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d := dst[j : j+4 : j+4]
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d[0] = c
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d[1] = c
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d[2] = c
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d[3] = 0xff
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j += 4
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i++
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}
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}
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case *image.Gray16:
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j := 0
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for y := y1; y < y2; y++ {
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i := y*img.Stride + x1*2
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for x := x1; x < x2; x++ {
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c := img.Pix[i]
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d := dst[j : j+4 : j+4]
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d[0] = c
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d[1] = c
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d[2] = c
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d[3] = 0xff
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j += 4
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i += 2
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}
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}
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case *image.YCbCr:
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j := 0
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x1 += img.Rect.Min.X
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x2 += img.Rect.Min.X
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y1 += img.Rect.Min.Y
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y2 += img.Rect.Min.Y
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hy := img.Rect.Min.Y / 2
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hx := img.Rect.Min.X / 2
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for y := y1; y < y2; y++ {
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iy := (y-img.Rect.Min.Y)*img.YStride + (x1 - img.Rect.Min.X)
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var yBase int
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switch img.SubsampleRatio {
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case image.YCbCrSubsampleRatio444, image.YCbCrSubsampleRatio422:
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yBase = (y - img.Rect.Min.Y) * img.CStride
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case image.YCbCrSubsampleRatio420, image.YCbCrSubsampleRatio440:
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yBase = (y/2 - hy) * img.CStride
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}
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for x := x1; x < x2; x++ {
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var ic int
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switch img.SubsampleRatio {
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case image.YCbCrSubsampleRatio444, image.YCbCrSubsampleRatio440:
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ic = yBase + (x - img.Rect.Min.X)
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case image.YCbCrSubsampleRatio422, image.YCbCrSubsampleRatio420:
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ic = yBase + (x/2 - hx)
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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
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// reverse reverses the data
|
|
// in contained pixel slice.
|
|
func reverse(pix []uint8) {
|
|
if len(pix) <= 4 {
|
|
return
|
|
}
|
|
i := 0
|
|
j := len(pix) - 4
|
|
for i < j {
|
|
pi := pix[i : i+4 : i+4]
|
|
pj := pix[j : j+4 : j+4]
|
|
pi[0], pj[0] = pj[0], pi[0]
|
|
pi[1], pj[1] = pj[1], pi[1]
|
|
pi[2], pj[2] = pj[2], pi[2]
|
|
pi[3], pj[3] = pj[3], pi[3]
|
|
i += 4
|
|
j -= 4
|
|
}
|
|
}
|
|
|
|
// clampFloat rounds and clamps float64 value to fit into uint8.
|
|
func clampFloat(x float64) uint8 {
|
|
v := int64(x + 0.5)
|
|
if v > 255 {
|
|
return 255
|
|
}
|
|
if v > 0 {
|
|
return uint8(v)
|
|
}
|
|
return 0
|
|
}
|