vcl/source/bitmap/BitmapMonochromeFilter.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/BitmapMonochromeFilter.hxx>
  12 #include <vcl/BitmapWriteAccess.hxx>
  13
  14 BitmapEx BitmapMonochromeFilter::execute(BitmapEx const& aBitmapEx) const
  15 {
  16     Bitmap aBitmap = aBitmapEx.GetBitmap();
  17     BitmapScopedReadAccess pReadAcc(aBitmap);
  18     if (!pReadAcc)
  19         return BitmapEx();
  20
  21     Bitmap aNewBmp(aBitmap.GetSizePixel(), vcl::PixelFormat::N8_BPP, &Bitmap::GetGreyPalette(256));
  22     BitmapScopedWriteAccess pWriteAcc(aNewBmp);
  23     if (!pWriteAcc)
  24         return BitmapEx();
  25
  26     const BitmapColor aBlack(pWriteAcc->GetBestMatchingColor(COL_BLACK));
  27     const BitmapColor aWhite(pWriteAcc->GetBestMatchingColor(COL_WHITE));
  28     const sal_Int32 nWidth = pWriteAcc->Width();
  29     const sal_Int32 nHeight = pWriteAcc->Height();
  30
  31     if (pReadAcc->HasPalette())
  32     {
  33         for (sal_Int32 nY = 0; nY < nHeight; nY++)
  34         {
  35             Scanline pScanline = pWriteAcc->GetScanline(nY);
  36             Scanline pScanlineRead = pReadAcc->GetScanline(nY);
  37             for (sal_Int32 nX = 0; nX < nWidth; nX++)
  38             {
  39                 const sal_uInt8 cIndex = pReadAcc->GetIndexFromData(pScanlineRead, nX);
  40                 if (pReadAcc->GetPaletteColor(cIndex).GetLuminance() >= mcThreshold)
  41                 {
  42                     pWriteAcc->SetPixelOnData(pScanline, nX, aWhite);
  43                 }
  44                 else
  45                 {
  46                     pWriteAcc->SetPixelOnData(pScanline, nX, aBlack);
  47                 }
  48             }
  49         }
  50     }
  51     else
  52     {
  53         for (sal_Int32 nY = 0; nY < nHeight; nY++)
  54         {
  55             Scanline pScanline = pWriteAcc->GetScanline(nY);
  56             Scanline pScanlineRead = pReadAcc->GetScanline(nY);
  57             for (sal_Int32 nX = 0; nX < nWidth; nX++)
  58             {
  59                 if (pReadAcc->GetPixelFromData(pScanlineRead, nX).GetLuminance() >= mcThreshold)
  60                 {
  61                     pWriteAcc->SetPixelOnData(pScanline, nX, aWhite);
  62                 }
  63                 else
  64                 {
  65                     pWriteAcc->SetPixelOnData(pScanline, nX, aBlack);
  66                 }
  67             }
  68         }
  69     }
  70
  71     pWriteAcc.reset();
  72     pReadAcc.reset();
  73
  74     const MapMode aMap(aBitmap.GetPrefMapMode());
  75     const Size aSize(aBitmap.GetPrefSize());
  76
  77     aBitmap = std::move(aNewBmp);
  78
  79     aBitmap.SetPrefMapMode(aMap);
  80     aBitmap.SetPrefSize(aSize);
  81
  82     return BitmapEx(aBitmap);
  83 }
  84
  85 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */