diff options
Diffstat (limited to 'vcl/source/bitmap/BitmapSobelGreyFilter.cxx')
| -rw-r--r-- | vcl/source/bitmap/BitmapSobelGreyFilter.cxx | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/vcl/source/bitmap/BitmapSobelGreyFilter.cxx b/vcl/source/bitmap/BitmapSobelGreyFilter.cxx new file mode 100644 index 000000000..dd77d633a --- /dev/null +++ b/vcl/source/bitmap/BitmapSobelGreyFilter.cxx @@ -0,0 +1,171 @@ +/* -*- 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/BitmapSobelGreyFilter.hxx> + +#include <bitmap/BitmapWriteAccess.hxx> + +#include <algorithm> + +BitmapEx BitmapSobelGreyFilter::execute(BitmapEx const& rBitmapEx) const +{ + Bitmap aBitmap(rBitmapEx.GetBitmap()); + + bool bRet = aBitmap.ImplMakeGreyscales(); + + if (bRet) + { + bRet = false; + + Bitmap::ScopedReadAccess pReadAcc(aBitmap); + + if (pReadAcc) + { + Bitmap aNewBmp(aBitmap.GetSizePixel(), vcl::PixelFormat::N8_BPP, + &pReadAcc->GetPalette()); + BitmapScopedWriteAccess pWriteAcc(aNewBmp); + + if (pWriteAcc) + { + BitmapColor aGrey(sal_uInt8(0)); + const sal_Int32 nWidth = pWriteAcc->Width(); + const sal_Int32 nHeight = pWriteAcc->Height(); + const sal_Int32 nMask111 = -1, nMask121 = 0, nMask131 = 1; + const sal_Int32 nMask211 = -2, nMask221 = 0, nMask231 = 2; + const sal_Int32 nMask311 = -1, nMask321 = 0, nMask331 = 1; + const sal_Int32 nMask112 = 1, nMask122 = 2, nMask132 = 1; + const sal_Int32 nMask212 = 0, nMask222 = 0, nMask232 = 0; + const sal_Int32 nMask312 = -1, nMask322 = -2, nMask332 = -1; + sal_Int32 nGrey11, nGrey12, nGrey13; + sal_Int32 nGrey21, nGrey22, nGrey23; + sal_Int32 nGrey31, nGrey32, nGrey33; + std::unique_ptr<long[]> pHMap(new long[nWidth + 2]); + std::unique_ptr<long[]> pVMap(new long[nHeight + 2]); + sal_Int32 nX, nY, nSum1, nSum2; + + // fill mapping tables + pHMap[0] = 0; + + for (nX = 1; nX <= nWidth; nX++) + { + pHMap[nX] = nX - 1; + } + + pHMap[nWidth + 1] = nWidth - 1; + + pVMap[0] = 0; + + for (nY = 1; nY <= nHeight; nY++) + { + pVMap[nY] = nY - 1; + } + + pVMap[nHeight + 1] = nHeight - 1; + + for (nY = 0; nY < nHeight; nY++) + { + nGrey11 = pReadAcc->GetPixel(pVMap[nY], pHMap[0]).GetIndex(); + nGrey12 = pReadAcc->GetPixel(pVMap[nY], pHMap[1]).GetIndex(); + nGrey13 = pReadAcc->GetPixel(pVMap[nY], pHMap[2]).GetIndex(); + nGrey21 = pReadAcc->GetPixel(pVMap[nY + 1], pHMap[0]).GetIndex(); + nGrey22 = pReadAcc->GetPixel(pVMap[nY + 1], pHMap[1]).GetIndex(); + nGrey23 = pReadAcc->GetPixel(pVMap[nY + 1], pHMap[2]).GetIndex(); + nGrey31 = pReadAcc->GetPixel(pVMap[nY + 2], pHMap[0]).GetIndex(); + nGrey32 = pReadAcc->GetPixel(pVMap[nY + 2], pHMap[1]).GetIndex(); + nGrey33 = pReadAcc->GetPixel(pVMap[nY + 2], pHMap[2]).GetIndex(); + + Scanline pScanline = pWriteAcc->GetScanline(nY); + for (nX = 0; nX < nWidth; nX++) + { + nSum1 = nSum2 = 0; + + nSum1 += nMask111 * nGrey11; + nSum2 += nMask112 * nGrey11; + + nSum1 += nMask121 * nGrey12; + nSum2 += nMask122 * nGrey12; + + nSum1 += nMask131 * nGrey13; + nSum2 += nMask132 * nGrey13; + + nSum1 += nMask211 * nGrey21; + nSum2 += nMask212 * nGrey21; + + nSum1 += nMask221 * nGrey22; + nSum2 += nMask222 * nGrey22; + + nSum1 += nMask231 * nGrey23; + nSum2 += nMask232 * nGrey23; + + nSum1 += nMask311 * nGrey31; + nSum2 += nMask312 * nGrey31; + + nSum1 += nMask321 * nGrey32; + nSum2 += nMask322 * nGrey32; + + nSum1 += nMask331 * nGrey33; + nSum2 += nMask332 * nGrey33; + + nSum1 = static_cast<sal_Int32>( + sqrt(static_cast<double>(nSum1 * nSum1 + nSum2 * nSum2))); + + aGrey.SetIndex(~static_cast<sal_uInt8>( + std::clamp(nSum1, sal_Int32(0), sal_Int32(255)))); + pWriteAcc->SetPixelOnData(pScanline, nX, aGrey); + + if (nX < (nWidth - 1)) + { + const sal_Int32 nNextX = pHMap[nX + 3]; + + nGrey11 = nGrey12; + nGrey12 = nGrey13; + nGrey13 = pReadAcc->GetPixel(pVMap[nY], nNextX).GetIndex(); + nGrey21 = nGrey22; + nGrey22 = nGrey23; + nGrey23 = pReadAcc->GetPixel(pVMap[nY + 1], nNextX).GetIndex(); + nGrey31 = nGrey32; + nGrey32 = nGrey33; + nGrey33 = pReadAcc->GetPixel(pVMap[nY + 2], nNextX).GetIndex(); + } + } + } + + pHMap.reset(); + pVMap.reset(); + pWriteAcc.reset(); + bRet = true; + } + + pReadAcc.reset(); + + if (bRet) + { + const MapMode aMap(aBitmap.GetPrefMapMode()); + const Size aPrefSize(aBitmap.GetPrefSize()); + + aBitmap = aNewBmp; + + aBitmap.SetPrefMapMode(aMap); + aBitmap.SetPrefSize(aPrefSize); + } + } + } + + if (bRet) + return BitmapEx(aBitmap); + + return BitmapEx(); +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |