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blender-archive/source/blender/compositor/operations/COM_CalculateStandardDeviationOperation.cpp
Manuel Castilla 4dc5920525 Fix CalculateStandardDeviationOperation incorrect results for R G B channels
Standard deviation formula wasn't being applied correctly when selecting
R G B cases. Issue is there since Blender 2.64 as it was incorrectly
ported over from the previous compositor.

Reviewed By: Sergey Sharybin, Jeroen Bakker

Differential Revision: https://developer.blender.org/D9384
2020-11-13 08:20:15 +01:00

101 lines
3.2 KiB
C++

/*
* 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
* of the License, 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright 2011, Blender Foundation.
*/
#include "COM_CalculateStandardDeviationOperation.h"
#include "BLI_math.h"
#include "BLI_utildefines.h"
#include "IMB_colormanagement.h"
CalculateStandardDeviationOperation::CalculateStandardDeviationOperation()
{
/* pass */
}
void CalculateStandardDeviationOperation::executePixel(float output[4],
int /*x*/,
int /*y*/,
void * /*data*/)
{
output[0] = this->m_standardDeviation;
}
void *CalculateStandardDeviationOperation::initializeTileData(rcti *rect)
{
lockMutex();
if (!this->m_iscalculated) {
MemoryBuffer *tile = (MemoryBuffer *)this->m_imageReader->initializeTileData(rect);
CalculateMeanOperation::calculateMean(tile);
this->m_standardDeviation = 0.0f;
float *buffer = tile->getBuffer();
int size = tile->getWidth() * tile->getHeight();
int pixels = 0;
float sum = 0.0f;
float mean = this->m_result;
for (int i = 0, offset = 0; i < size; i++, offset += 4) {
if (buffer[offset + 3] > 0) {
pixels++;
switch (this->m_setting) {
case 1: /* rgb combined */
{
float value = IMB_colormanagement_get_luminance(&buffer[offset]);
sum += (value - mean) * (value - mean);
break;
}
case 2: /* red */
{
float value = buffer[offset];
sum += (value - mean) * (value - mean);
break;
}
case 3: /* green */
{
float value = buffer[offset + 1];
sum += (value - mean) * (value - mean);
break;
}
case 4: /* blue */
{
float value = buffer[offset + 2];
sum += (value - mean) * (value - mean);
break;
}
case 5: /* luminance */
{
float yuv[3];
rgb_to_yuv(buffer[offset],
buffer[offset + 1],
buffer[offset + 2],
&yuv[0],
&yuv[1],
&yuv[2],
BLI_YUV_ITU_BT709);
sum += (yuv[0] - mean) * (yuv[0] - mean);
break;
}
}
}
}
this->m_standardDeviation = sqrt(sum / (float)(pixels - 1));
this->m_iscalculated = true;
}
unlockMutex();
return nullptr;
}