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-rw-r--r--vcl/source/bitmap/BitmapColorQuantizationFilter.cxx224
1 files changed, 224 insertions, 0 deletions
diff --git a/vcl/source/bitmap/BitmapColorQuantizationFilter.cxx b/vcl/source/bitmap/BitmapColorQuantizationFilter.cxx
new file mode 100644
index 000000000..45d39add3
--- /dev/null
+++ b/vcl/source/bitmap/BitmapColorQuantizationFilter.cxx
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ */
+
+#include <sal/config.h>
+
+#include <vcl/bitmap.hxx>
+#include <vcl/bitmapex.hxx>
+#include <vcl/BitmapColorQuantizationFilter.hxx>
+
+#include <bitmap/BitmapWriteAccess.hxx>
+
+#include <algorithm>
+#include <cstdlib>
+
+BitmapEx BitmapColorQuantizationFilter::execute(BitmapEx const& aBitmapEx) const
+{
+ Bitmap aBitmap = aBitmapEx.GetBitmap();
+
+ bool bRet = false;
+
+ if (vcl::numberOfColors(aBitmap.getPixelFormat()) <= sal_Int64(mnNewColorCount))
+ {
+ bRet = true;
+ }
+ else
+ {
+ Bitmap::ScopedReadAccess pRAcc(aBitmap);
+
+ auto const cappedNewColorCount = std::min(mnNewColorCount, sal_uInt16(256));
+
+ if (pRAcc)
+ {
+ const sal_uInt32 nValidBits = 4;
+ const sal_uInt32 nRightShiftBits = 8 - nValidBits;
+ const sal_uInt32 nLeftShiftBits1 = nValidBits;
+ const sal_uInt32 nLeftShiftBits2 = nValidBits << 1;
+ const sal_uInt32 nColorsPerComponent = 1 << nValidBits;
+ const sal_uInt32 nColorOffset = 256 / nColorsPerComponent;
+ const sal_uInt32 nTotalColors
+ = nColorsPerComponent * nColorsPerComponent * nColorsPerComponent;
+ const sal_Int32 nWidth = pRAcc->Width();
+ const sal_Int32 nHeight = pRAcc->Height();
+ std::unique_ptr<PopularColorCount[]> pCountTable(new PopularColorCount[nTotalColors]);
+
+ memset(pCountTable.get(), 0, nTotalColors * sizeof(PopularColorCount));
+
+ for (sal_Int32 nR = 0, nIndex = 0; nR < 256; nR += nColorOffset)
+ {
+ for (sal_Int32 nG = 0; nG < 256; nG += nColorOffset)
+ {
+ for (sal_Int32 nB = 0; nB < 256; nB += nColorOffset)
+ {
+ pCountTable[nIndex].mnIndex = nIndex;
+ nIndex++;
+ }
+ }
+ }
+
+ if (pRAcc->HasPalette())
+ {
+ for (sal_Int32 nY = 0; nY < nHeight; nY++)
+ {
+ Scanline pScanlineRead = pRAcc->GetScanline(nY);
+ for (sal_Int32 nX = 0; nX < nWidth; nX++)
+ {
+ const BitmapColor& rCol
+ = pRAcc->GetPaletteColor(pRAcc->GetIndexFromData(pScanlineRead, nX));
+ pCountTable[((static_cast<sal_uInt32>(rCol.GetRed()) >> nRightShiftBits)
+ << nLeftShiftBits2)
+ | ((static_cast<sal_uInt32>(rCol.GetGreen()) >> nRightShiftBits)
+ << nLeftShiftBits1)
+ | (static_cast<sal_uInt32>(rCol.GetBlue()) >> nRightShiftBits)]
+ .mnCount++;
+ }
+ }
+ }
+ else
+ {
+ for (sal_Int32 nY = 0; nY < nHeight; nY++)
+ {
+ Scanline pScanlineRead = pRAcc->GetScanline(nY);
+ for (sal_Int32 nX = 0; nX < nWidth; nX++)
+ {
+ const BitmapColor aCol(pRAcc->GetPixelFromData(pScanlineRead, nX));
+ pCountTable[((static_cast<sal_uInt32>(aCol.GetRed()) >> nRightShiftBits)
+ << nLeftShiftBits2)
+ | ((static_cast<sal_uInt32>(aCol.GetGreen()) >> nRightShiftBits)
+ << nLeftShiftBits1)
+ | (static_cast<sal_uInt32>(aCol.GetBlue()) >> nRightShiftBits)]
+ .mnCount++;
+ }
+ }
+ }
+
+ BitmapPalette aNewPal(cappedNewColorCount);
+
+ std::qsort(pCountTable.get(), nTotalColors, sizeof(PopularColorCount),
+ [](const void* p1, const void* p2) {
+ int nRet;
+
+ if (static_cast<PopularColorCount const*>(p1)->mnCount
+ < static_cast<PopularColorCount const*>(p2)->mnCount)
+ nRet = 1;
+ else if (static_cast<PopularColorCount const*>(p1)->mnCount
+ == static_cast<PopularColorCount const*>(p2)->mnCount)
+ nRet = 0;
+ else
+ nRet = -1;
+
+ return nRet;
+ });
+
+ for (sal_uInt16 n = 0; n < cappedNewColorCount; n++)
+ {
+ const PopularColorCount& rPop = pCountTable[n];
+ aNewPal[n] = BitmapColor(
+ static_cast<sal_uInt8>((rPop.mnIndex >> nLeftShiftBits2) << nRightShiftBits),
+ static_cast<sal_uInt8>(
+ ((rPop.mnIndex >> nLeftShiftBits1) & (nColorsPerComponent - 1))
+ << nRightShiftBits),
+ static_cast<sal_uInt8>((rPop.mnIndex & (nColorsPerComponent - 1))
+ << nRightShiftBits));
+ }
+
+ Bitmap aNewBmp(aBitmap.GetSizePixel(), vcl::PixelFormat::N8_BPP, &aNewPal);
+ BitmapScopedWriteAccess pWAcc(aNewBmp);
+
+ if (pWAcc)
+ {
+ BitmapColor aDstCol(sal_uInt8(0));
+ std::unique_ptr<sal_uInt8[]> pIndexMap(new sal_uInt8[nTotalColors]);
+
+ for (sal_Int32 nR = 0, nIndex = 0; nR < 256; nR += nColorOffset)
+ {
+ for (sal_Int32 nG = 0; nG < 256; nG += nColorOffset)
+ {
+ for (sal_Int32 nB = 0; nB < 256; nB += nColorOffset)
+ {
+ pIndexMap[nIndex++] = static_cast<sal_uInt8>(aNewPal.GetBestIndex(
+ BitmapColor(static_cast<sal_uInt8>(nR), static_cast<sal_uInt8>(nG),
+ static_cast<sal_uInt8>(nB))));
+ }
+ }
+ }
+
+ if (pRAcc->HasPalette())
+ {
+ for (sal_Int32 nY = 0; nY < nHeight; nY++)
+ {
+ Scanline pScanline = pWAcc->GetScanline(nY);
+ Scanline pScanlineRead = pRAcc->GetScanline(nY);
+ for (sal_Int32 nX = 0; nX < nWidth; nX++)
+ {
+ const BitmapColor& rCol = pRAcc->GetPaletteColor(
+ pRAcc->GetIndexFromData(pScanlineRead, nX));
+ aDstCol.SetIndex(pIndexMap[((static_cast<sal_uInt32>(rCol.GetRed())
+ >> nRightShiftBits)
+ << nLeftShiftBits2)
+ | ((static_cast<sal_uInt32>(rCol.GetGreen())
+ >> nRightShiftBits)
+ << nLeftShiftBits1)
+ | (static_cast<sal_uInt32>(rCol.GetBlue())
+ >> nRightShiftBits)]);
+ pWAcc->SetPixelOnData(pScanline, nX, aDstCol);
+ }
+ }
+ }
+ else
+ {
+ for (sal_Int32 nY = 0; nY < nHeight; nY++)
+ {
+ Scanline pScanline = pWAcc->GetScanline(nY);
+ Scanline pScanlineRead = pRAcc->GetScanline(nY);
+
+ for (sal_Int32 nX = 0; nX < nWidth; nX++)
+ {
+ const BitmapColor aCol(pRAcc->GetPixelFromData(pScanlineRead, nX));
+ aDstCol.SetIndex(pIndexMap[((static_cast<sal_uInt32>(aCol.GetRed())
+ >> nRightShiftBits)
+ << nLeftShiftBits2)
+ | ((static_cast<sal_uInt32>(aCol.GetGreen())
+ >> nRightShiftBits)
+ << nLeftShiftBits1)
+ | (static_cast<sal_uInt32>(aCol.GetBlue())
+ >> nRightShiftBits)]);
+ pWAcc->SetPixelOnData(pScanline, nX, aDstCol);
+ }
+ }
+ }
+
+ pWAcc.reset();
+ bRet = true;
+ }
+
+ pCountTable.reset();
+ pRAcc.reset();
+
+ if (bRet)
+ {
+ const MapMode aMap(aBitmap.GetPrefMapMode());
+ const Size aSize(aBitmap.GetPrefSize());
+
+ aBitmap = aNewBmp;
+
+ aBitmap.SetPrefMapMode(aMap);
+ aBitmap.SetPrefSize(aSize);
+ }
+ }
+ }
+
+ if (bRet)
+ return BitmapEx(aBitmap);
+
+ return BitmapEx();
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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