vcl/source/bitmap/BitmapMedianFilter.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  */
  10
  11 #include <vcl/bitmap.hxx>
  12 #include <vcl/bitmapex.hxx>
  13 #include <vcl/BitmapMedianFilter.hxx>
  14
  15 #include <bitmap/BitmapWriteAccess.hxx>
  16
  17 #define S2(a, b)                                                                                   \
  18     {                                                                                              \
  19         tools::Long t;                                                                             \
  20         if ((t = b - a) < 0)                                                                       \
  21         {                                                                                          \
  22             a += t;                                                                                \
  23             b -= t;                                                                                \
  24         }                                                                                          \
  25     }
  26 #define MN3(a, b, c)                                                                               \
  27     S2(a, b);                                                                                      \
  28     S2(a, c);
  29 #define MX3(a, b, c)                                                                               \
  30     S2(b, c);                                                                                      \
  31     S2(a, c);
  32 #define MNMX3(a, b, c)                                                                             \
  33     MX3(a, b, c);                                                                                  \
  34     S2(a, b);
  35 #define MNMX4(a, b, c, d)                                                                          \
  36     S2(a, b);                                                                                      \
  37     S2(c, d);                                                                                      \
  38     S2(a, c);                                                                                      \
  39     S2(b, d);
  40 #define MNMX5(a, b, c, d, e)                                                                       \
  41     S2(a, b);                                                                                      \
  42     S2(c, d);                                                                                      \
  43     MN3(a, c, e);                                                                                  \
  44     MX3(b, d, e);
  45 #define MNMX6(a, b, c, d, e, f)                                                                    \
  46     S2(a, d);                                                                                      \
  47     S2(b, e);                                                                                      \
  48     S2(c, f);                                                                                      \
  49     MN3(a, b, c);                                                                                  \
  50     MX3(d, e, f);
  51
  52 BitmapEx BitmapMedianFilter::execute(BitmapEx const& rBitmapEx) const
  53 {
  54     Bitmap aBitmap(rBitmapEx.GetBitmap());
  55
  56     Bitmap::ScopedReadAccess pReadAcc(aBitmap);
  57     bool bRet = false;
  58
  59     if (pReadAcc)
  60     {
  61         Bitmap aNewBmp(aBitmap.GetSizePixel(), vcl::PixelFormat::N24_BPP);
  62         BitmapScopedWriteAccess pWriteAcc(aNewBmp);
  63
  64         if (pWriteAcc)
  65         {
  66             const tools::Long nWidth = pWriteAcc->Width(), nWidth2 = nWidth + 2;
  67             const tools::Long nHeight = pWriteAcc->Height(), nHeight2 = nHeight + 2;
  68             std::unique_ptr<tools::Long[]> pColm(new tools::Long[nWidth2]);
  69             std::unique_ptr<tools::Long[]> pRows(new tools::Long[nHeight2]);
  70             std::unique_ptr<BitmapColor[]> pColRow1(new BitmapColor[nWidth2]);
  71             std::unique_ptr<BitmapColor[]> pColRow2(new BitmapColor[nWidth2]);
  72             std::unique_ptr<BitmapColor[]> pColRow3(new BitmapColor[nWidth2]);
  73             BitmapColor* pRowTmp1 = pColRow1.get();
  74             BitmapColor* pRowTmp2 = pColRow2.get();
  75             BitmapColor* pRowTmp3 = pColRow3.get();
  76             BitmapColor* pColor;
  77             tools::Long nY, nX, i;
  78             tools::Long nR1, nR2, nR3, nR4, nR5, nR6, nR7, nR8, nR9;
  79             tools::Long nG1, nG2, nG3, nG4, nG5, nG6, nG7, nG8, nG9;
  80             tools::Long nB1, nB2, nB3, nB4, nB5, nB6, nB7, nB8, nB9;
  81
  82             // create column LUT
  83             for (i = 0; i < nWidth2; i++)
  84                 pColm[i] = (i > 0) ? (i - 1) : 0;
  85
  86             pColm[nWidth + 1] = pColm[nWidth];
  87
  88             // create row LUT
  89             for (i = 0; i < nHeight2; i++)
  90                 pRows[i] = (i > 0) ? (i - 1) : 0;
  91
  92             pRows[nHeight + 1] = pRows[nHeight];
  93
  94             // read first three rows of bitmap color
  95             if (nHeight2 > 2)
  96             {
  97                 for (i = 0; i < nWidth2; i++)
  98                 {
  99                     pColRow1[i] = pReadAcc->GetColor(pRows[0], pColm[i]);
 100                     pColRow2[i] = pReadAcc->GetColor(pRows[1], pColm[i]);
 101                     pColRow3[i] = pReadAcc->GetColor(pRows[2], pColm[i]);
 102                 }
 103             }
 104
 105             // do median filtering
 106             for (nY = 0; nY < nHeight;)
 107             {
 108                 Scanline pScanline = pWriteAcc->GetScanline(nY);
 109                 for (nX = 0; nX < nWidth; nX++)
 110                 {
 111                     pColor = pRowTmp1 + nX;
 112                     nR1 = pColor->GetRed();
 113                     nG1 = pColor->GetGreen();
 114                     nB1 = pColor->GetBlue();
 115                     nR2 = (++pColor)->GetRed();
 116                     nG2 = pColor->GetGreen();
 117                     nB2 = pColor->GetBlue();
 118                     nR3 = (++pColor)->GetRed();
 119                     nG3 = pColor->GetGreen();
 120                     nB3 = pColor->GetBlue();
 121
 122                     pColor = pRowTmp2 + nX;
 123                     nR4 = pColor->GetRed();
 124                     nG4 = pColor->GetGreen();
 125                     nB4 = pColor->GetBlue();
 126                     nR5 = (++pColor)->GetRed();
 127                     nG5 = pColor->GetGreen();
 128                     nB5 = pColor->GetBlue();
 129                     nR6 = (++pColor)->GetRed();
 130                     nG6 = pColor->GetGreen();
 131                     nB6 = pColor->GetBlue();
 132
 133                     pColor = pRowTmp3 + nX;
 134                     nR7 = pColor->GetRed();
 135                     nG7 = pColor->GetGreen();
 136                     nB7 = pColor->GetBlue();
 137                     nR8 = (++pColor)->GetRed();
 138                     nG8 = pColor->GetGreen();
 139                     nB8 = pColor->GetBlue();
 140                     nR9 = (++pColor)->GetRed();
 141                     nG9 = pColor->GetGreen();
 142                     nB9 = pColor->GetBlue();
 143
 144                     MNMX6(nR1, nR2, nR3, nR4, nR5, nR6);
 145                     MNMX5(nR7, nR2, nR3, nR4, nR5);
 146                     MNMX4(nR8, nR2, nR3, nR4);
 147                     MNMX3(nR9, nR2, nR3);
 148
 149                     MNMX6(nG1, nG2, nG3, nG4, nG5, nG6);
 150                     MNMX5(nG7, nG2, nG3, nG4, nG5);
 151                     MNMX4(nG8, nG2, nG3, nG4);
 152                     MNMX3(nG9, nG2, nG3);
 153
 154                     MNMX6(nB1, nB2, nB3, nB4, nB5, nB6);
 155                     MNMX5(nB7, nB2, nB3, nB4, nB5);
 156                     MNMX4(nB8, nB2, nB3, nB4);
 157                     MNMX3(nB9, nB2, nB3);
 158
 159                     // set destination color
 160                     pWriteAcc->SetPixelOnData(pScanline, nX,
 161                                               BitmapColor(static_cast<sal_uInt8>(nR2),
 162                                                           static_cast<sal_uInt8>(nG2),
 163                                                           static_cast<sal_uInt8>(nB2)));
 164                 }
 165
 166                 if (++nY < nHeight)
 167                 {
 168                     if (pRowTmp1 == pColRow1.get())
 169                     {
 170                         pRowTmp1 = pColRow2.get();
 171                         pRowTmp2 = pColRow3.get();
 172                         pRowTmp3 = pColRow1.get();
 173                     }
 174                     else if (pRowTmp1 == pColRow2.get())
 175                     {
 176                         pRowTmp1 = pColRow3.get();
 177                         pRowTmp2 = pColRow1.get();
 178                         pRowTmp3 = pColRow2.get();
 179                     }
 180                     else
 181                     {
 182                         pRowTmp1 = pColRow1.get();
 183                         pRowTmp2 = pColRow2.get();
 184                         pRowTmp3 = pColRow3.get();
 185                     }
 186
 187                     for (i = 0; i < nWidth2; i++)
 188                         pRowTmp3[i] = pReadAcc->GetColor(pRows[nY + 2], pColm[i]);
 189                 }
 190             }
 191
 192             pWriteAcc.reset();
 193
 194             bRet = true;
 195         }
 196
 197         pReadAcc.reset();
 198
 199         if (bRet)
 200         {
 201             const MapMode aMap(aBitmap.GetPrefMapMode());
 202             const Size aPrefSize(aBitmap.GetPrefSize());
 203
 204             aBitmap = aNewBmp;
 205
 206             aBitmap.SetPrefMapMode(aMap);
 207             aBitmap.SetPrefSize(aPrefSize);
 208         }
 209     }
 210
 211     if (bRet)
 212         return BitmapEx(aBitmap);
 213
 214     return BitmapEx();
 215 }
 216
 217 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */