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/* ============================================================
*
* This file is a part of digiKam project
* http://www.digikam.org
*
* Date : 2005-05-25
* Description : Charcoal threaded image filter.
*
* Copyright (C) 2005-2007 by Gilles Caulier <caulier dot gilles at gmail dot com>
*
* Original Charcoal algorithm copyright 2002
* by Daniel M. Duley <mosfet@kde.org> from KImageEffect API.
*
* 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.
*
* ============================================================ */
#define SQ2PI 2.50662827463100024161235523934010416269302368164062
#define Epsilon 1.0e-12
// C++ includes.
#include <cmath>
// Local includes.
#include "ddebug.h"
#include "dimg.h"
#include "dimggaussianblur.h"
#include "dimgimagefilters.h"
#include "charcoal.h"
namespace DigikamCharcoalImagesPlugin
{
Charcoal::Charcoal(Digikam::DImg *orgImage, TQObject *parent, double pencil, double smooth)
: Digikam::DImgThreadedFilter(orgImage, parent, "Charcoal")
{
m_pencil = pencil;
m_smooth = smooth;
initFilter();
}
void Charcoal::filterImage(void)
{
if (m_orgImage.isNull())
{
DWarning() << k_funcinfo << "No image data available!"
<< endl;
return;
}
if (m_pencil <= 0.0)
{
m_destImage = m_orgImage;
return;
}
// -- Applying Edge effect -----------------------------------------------
long i=0;
int kernelWidth = getOptimalKernelWidth(m_pencil, m_smooth);
if((int)m_orgImage.width() < kernelWidth)
{
DWarning() << k_funcinfo << "Image is smaller than radius!"
<< endl;
return;
}
double *kernel = new double[kernelWidth*kernelWidth];
if(!kernel)
{
DWarning() << k_funcinfo << "Unable to allocate memory!"
<< endl;
return;
}
for(i = 0 ; i < (kernelWidth*kernelWidth) ; i++)
kernel[i]=(-1.0);
kernel[i/2]=kernelWidth*kernelWidth-1.0;
convolveImage(kernelWidth, kernel);
delete [] kernel;
// -- Applying Gaussian blur effect ---------------------------------------
Digikam::DImgGaussianBlur(this, m_destImage, m_destImage, 50, 60, (int)(m_smooth/10.0));
if (m_cancel)
return;
// -- Applying strech contrast color effect -------------------------------
Digikam::DImgImageFilters().stretchContrastImage(m_destImage.bits(), m_destImage.width(),
m_destImage.height(), m_destImage.sixteenBit());
postProgress( 70 );
if (m_cancel)
return;
// -- Inverting image color -----------------------------------------------
Digikam::DImgImageFilters().invertImage(m_destImage.bits(), m_destImage.width(),
m_destImage.height(), m_destImage.sixteenBit());
postProgress( 80 );
if (m_cancel)
return;
// -- Convert to neutral black & white ------------------------------------
Digikam::DImgImageFilters().channelMixerImage(
m_destImage.bits(), m_destImage.width(),
m_destImage.height(), m_destImage.sixteenBit(), // Image data.
true, // Preserve luminosity.
true, // Monochrome.
0.3, 0.59 , 0.11, // Red channel gains.
0.0, 1.0, 0.0, // Green channel gains (not used).
0.0, 0.0, 1.0); // Blue channel gains (not used).
postProgress( 90 );
if (m_cancel)
return;
}
bool Charcoal::convolveImage(const unsigned int order, const double *kernel)
{
uint x, y;
int mx, my, sx, sy, mcx, mcy, progress;
long kernelWidth, i;
double red, green, blue, alpha, normalize=0.0;
double *k=0;
Digikam::DColor color;
kernelWidth = order;
if((kernelWidth % 2) == 0)
{
DWarning() << k_funcinfo << "Kernel width must be an odd number!"
<< endl;
return(false);
}
double *normal_kernel = new double[kernelWidth*kernelWidth];
if(!normal_kernel)
{
DWarning() << k_funcinfo << "Unable to allocate memory!"
<< endl;
return(false);
}
for(i=0 ; i < (kernelWidth*kernelWidth) ; i++)
normalize += kernel[i];
if(fabs(normalize) <= Epsilon)
normalize=1.0;
normalize = 1.0/normalize;
for(i=0 ; i < (kernelWidth*kernelWidth) ; i++)
normal_kernel[i] = normalize*kernel[i];
double maxClamp = m_destImage.sixteenBit() ? 16777215.0 : 65535.0;
for(y=0 ; !m_cancel && (y < m_destImage.height()) ; y++)
{
sy = y-(kernelWidth/2);
for(x=0 ; !m_cancel && (x < m_destImage.width()) ; x++)
{
k = normal_kernel;
red = green = blue = alpha = 0;
sy = y-(kernelWidth/2);
for(mcy=0 ; !m_cancel && (mcy < kernelWidth) ; mcy++, sy++)
{
my = sy < 0 ? 0 : sy > (int)m_destImage.height()-1 ? m_destImage.height()-1 : sy;
sx = x+(-kernelWidth/2);
for(mcx=0 ; !m_cancel && (mcx < kernelWidth) ; mcx++, sx++)
{
mx = sx < 0 ? 0 : sx > (int)m_destImage.width()-1 ? m_destImage.width()-1 : sx;
color = m_orgImage.getPixelColor(mx, my);
red += (*k)*(color.red() * 257.0);
green += (*k)*(color.green() * 257.0);
blue += (*k)*(color.blue() * 257.0);
alpha += (*k)*(color.alpha() * 257.0);
k++;
}
}
red = red < 0.0 ? 0.0 : red > maxClamp ? maxClamp : red+0.5;
green = green < 0.0 ? 0.0 : green > maxClamp ? maxClamp : green+0.5;
blue = blue < 0.0 ? 0.0 : blue > maxClamp ? maxClamp : blue+0.5;
alpha = alpha < 0.0 ? 0.0 : alpha > maxClamp ? maxClamp : alpha+0.5;
m_destImage.setPixelColor(x, y, Digikam::DColor((int)(red / 257UL), (int)(green / 257UL),
(int)(blue / 257UL), (int)(alpha / 257UL),
m_destImage.sixteenBit()));
}
progress = (int)(((double)y * 50.0) / m_destImage.height());
if ( progress%5 == 0 )
postProgress( progress );
}
delete [] normal_kernel;
return(true);
}
int Charcoal::getOptimalKernelWidth(double radius, double sigma)
{
double normalize, value;
long kernelWidth;
long u;
if(radius > 0.0)
return((int)(2.0*ceil(radius)+1.0));
for(kernelWidth=5; ;)
{
normalize=0.0;
for(u=(-kernelWidth/2) ; u <= (kernelWidth/2) ; u++)
normalize += exp(-((double) u*u)/(2.0*sigma*sigma))/(SQ2PI*sigma);
u = kernelWidth/2;
value = exp(-((double) u*u)/(2.0*sigma*sigma))/(SQ2PI*sigma)/normalize;
if((long)(65535*value) <= 0)
break;
kernelWidth+=2;
}
return((int)kernelWidth-2);
}
} // NameSpace DigikamCharcoalImagesPlugin
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