1 files changed, 202 insertions, 0 deletions
diff --git a/src/imageplugins/filmgrain/filmgrain.cpp b/src/imageplugins/filmgrain/filmgrain.cpp
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+++ b/src/imageplugins/filmgrain/filmgrain.cpp
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+/* ============================================================
+ *
+ * This file is a part of digiKam project
+ * http://www.digikam.org
+ *
+ * Date        : 2005-05-25
+ * Description : FilmGrain threaded image filter.
+ * 
+ * Copyright (C) 2005-2007 by Gilles Caulier <caulier dot gilles at gmail dot com>
+ * Copyright (C) 2005-2007 by Marcel Wiesweg <marcel dot wiesweg at gmx dot de>
+ * 
+ * This program is free software; you can redistribute it
+ * and/or modify it under the terms of the GNU General
+ * Public License as published by the Free Software Foundation;
+ * either version 2, or (at your option)
+ * any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * ============================================================ */
+
+// C++ includes.
+
+#include <cmath>
+#include <cstdlib>
+
+// TQt includes.
+
+#include <tqdatetime.h> 
+
+// Local includes.
+
+#include "ddebug.h"
+#include "dimg.h"
+#include "dimggaussianblur.h"
+#include "imagecurves.h"
+#include "imagehistogram.h"
+#include "dimgimagefilters.h"
+#include "filmgrain.h"
+
+namespace DigikamFilmGrainImagesPlugin
+{
+
+FilmGrain::FilmGrain(Digikam::DImg *orgImage, TQObject *parent, int sensibility)
+         : Digikam::DImgThreadedFilter(orgImage, parent, "FilmGrain")
+{
+    m_sensibility = sensibility;
+    initFilter();
+}
+
+void FilmGrain::filterImage(void)
+{
+    filmgrainImage(&m_orgImage, m_sensibility);
+}
+
+// This method is based on the Simulate Film grain tutorial from GimpGuru.org web site 
+// available at this url : http://www.gimpguru.org/Tutorials/FilmGrain
+
+void FilmGrain::filmgrainImage(Digikam::DImg *orgImage, int Sensibility)
+{
+    // Sensibility: 800..6400
+
+    if (Sensibility <= 0) return;
+
+    int Width = orgImage->width();
+    int Height = orgImage->height();
+    int bytesDepth = orgImage->bytesDepth();
+    bool sixteenBit = orgImage->sixteenBit();
+    uchar* data = orgImage->bits();
+
+    Digikam::DImg grain(Width, Height, sixteenBit);      // Grain blured without curves adjustment.
+    Digikam::DImg mask(Width, Height, sixteenBit);       // Grain mask with curves adjustment.
+    uchar* pGrainBits = grain.bits();
+    uchar* pMaskBits  = mask.bits();
+    uchar* pOutBits = m_destImage.bits(); // Destination image with merged grain mask and original.
+
+    int Noise, Shade, nRand, component, progress;
+    uchar *ptr;
+    Digikam::DColor blendData, grainData, maskData, outData;
+
+    if (sixteenBit)
+        Noise = (Sensibility / 10 + 1) * 256 - 1;
+    else
+        Noise = Sensibility / 10;
+
+    // This value controls the shading pixel effect between original image and grain mask.
+    if (sixteenBit)
+        Shade = (52 + 1) * 256 - 1;
+    else
+        Shade = 52;
+
+    TQDateTime dt = TQDateTime::currentDateTime();
+    TQDateTime Y2000( TQDate(2000, 1, 1), TQTime(0, 0, 0) );
+    uint seed = (uint) dt.secsTo(Y2000);
+
+    // Make gray grain mask.
+
+    grainData.setSixteenBit(sixteenBit);
+
+    for (int x = 0; !m_cancel && x < Width; x++)
+    {
+        for (int y = 0; !m_cancel && y < Height; y++)
+        {
+            ptr = pGrainBits + x*bytesDepth + (y*Width*bytesDepth);
+
+            nRand = (rand_r(&seed) % Noise) - (Noise / 2);
+            if (sixteenBit)
+                component = CLAMP(32768 + nRand, 0, 65535);
+            else
+                component = CLAMP(128 + nRand, 0, 255);
+
+            grainData.setRed  (component);
+            grainData.setGreen(component);
+            grainData.setBlue (component);
+            grainData.setAlpha(0);
+
+            grainData.setPixel(ptr);
+        }
+
+        // Update progress bar in dialog.
+        progress = (int) (((double)x * 25.0) / Width);
+
+        if (progress%5 == 0)
+            postProgress( progress );
+    }
+
+    // Smooth grain mask using gaussian blur with radius 1.
+    Digikam::DImgGaussianBlur(this, grain, grain, 25, 30, 1);
+
+    // Normally, film grain tends to be most noticeable in the midtones, and much less 
+    // so in the shadows and highlights. Adjust histogram curve to adjust grain like this.
+
+    Digikam::ImageCurves *grainCurves = new Digikam::ImageCurves(sixteenBit);
+
+    // We modify only global luminosity of the grain.
+    if (sixteenBit)
+    {
+        grainCurves->setCurvePoint(Digikam::ImageHistogram::ValueChannel, 0,  TQPoint(0,     0));
+        grainCurves->setCurvePoint(Digikam::ImageHistogram::ValueChannel, 8,  TQPoint(32768, 32768));
+        grainCurves->setCurvePoint(Digikam::ImageHistogram::ValueChannel, 16, TQPoint(65535, 0));
+    }
+    else
+    {
+        grainCurves->setCurvePoint(Digikam::ImageHistogram::ValueChannel, 0,  TQPoint(0,   0));
+        grainCurves->setCurvePoint(Digikam::ImageHistogram::ValueChannel, 8,  TQPoint(128, 128));
+        grainCurves->setCurvePoint(Digikam::ImageHistogram::ValueChannel, 16, TQPoint(255, 0));
+    }
+
+    // Calculate curves and lut to apply on grain.
+    grainCurves->curvesCalculateCurve(Digikam::ImageHistogram::ValueChannel);
+    grainCurves->curvesLutSetup(Digikam::ImageHistogram::AlphaChannel);
+    grainCurves->curvesLutProcess(pGrainBits, pMaskBits, Width, Height);
+
+    grain.reset();
+    delete grainCurves;
+
+    // Update progress bar in dialog.
+    postProgress( 40 );
+
+    // Merge src image with grain using shade coefficient.
+
+    int alpha;
+    // get composer for default blending
+    Digikam::DColorComposer *composer = Digikam::DColorComposer::getComposer(Digikam::DColorComposer::PorterDuffNone);
+
+    for (int x = 0; !m_cancel && x < Width; x++)
+    {
+        for (int y = 0; !m_cancel && y < Height; y++)
+        {
+            int offset = x*bytesDepth + (y*Width*bytesDepth);
+
+            // read color from orig image
+            blendData.setColor(data + offset, sixteenBit);
+            // read color from mask
+            maskData.setColor(pMaskBits + offset, sixteenBit);
+            // set shade as alpha value - it will be used as source alpha when blending
+            maskData.setAlpha(Shade);
+
+            // compose, write result to blendData.
+            // Preserve alpha, do not blend it (taken from old algorithm - correct?)
+            alpha = blendData.alpha();
+            composer->compose(blendData, maskData);
+            blendData.setAlpha(alpha);
+
+            // write to destination
+            blendData.setPixel(pOutBits + offset);
+        }
+
+        // Update progress bar in dialog.
+        progress = (int) (50.0 + ((double)x * 50.0) / Width);
+
+        if (progress%5 == 0)
+           postProgress( progress );
+    }
+
+    delete composer;
+}
+
+}  // NameSpace DigikamFilmGrainImagesPlugin