Lukas Tönne
c566e408e4
Distinguish the 3 different methods for acquiring pixel color values (executePixel, executePixelSampled, executePixelFiltered). This makes it easier to keep track of the different sampling methods (and works nicer with IDEs that do code parsing). Differential Revision: http://developer.blender.org/D7
102 lines
3.0 KiB
C++
102 lines
3.0 KiB
C++
/*
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* Copyright 2011, Blender Foundation.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* Contributor:
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* Dalai Felinto
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*/
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#include "COM_ChromaMatteOperation.h"
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#include "BLI_math.h"
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ChromaMatteOperation::ChromaMatteOperation() : NodeOperation()
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{
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addInputSocket(COM_DT_COLOR);
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addInputSocket(COM_DT_COLOR);
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addOutputSocket(COM_DT_VALUE);
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this->m_inputImageProgram = NULL;
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this->m_inputKeyProgram = NULL;
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}
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void ChromaMatteOperation::initExecution()
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{
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this->m_inputImageProgram = this->getInputSocketReader(0);
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this->m_inputKeyProgram = this->getInputSocketReader(1);
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}
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void ChromaMatteOperation::deinitExecution()
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{
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this->m_inputImageProgram = NULL;
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this->m_inputKeyProgram = NULL;
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}
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void ChromaMatteOperation::executePixelSampled(float output[4], float x, float y, PixelSampler sampler)
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{
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float inKey[4];
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float inImage[4];
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const float acceptance = this->m_settings->t1; /* in radians */
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const float cutoff = this->m_settings->t2; /* in radians */
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const float gain = this->m_settings->fstrength;
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float x_angle, z_angle, alpha;
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float theta, beta;
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float kfg;
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this->m_inputKeyProgram->readSampled(inKey, x, y, sampler);
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this->m_inputImageProgram->readSampled(inImage, x, y, sampler);
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/* store matte(alpha) value in [0] to go with
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* COM_SetAlphaOperation and the Value output
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*/
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/* Algorithm from book "Video Demistified," does not include the spill reduction part */
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/* find theta, the angle that the color space should be rotated based on key */
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theta = atan2(inKey[2], inKey[1]);
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/*rotate the cb and cr into x/z space */
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x_angle = inImage[1] * cosf(theta) + inImage[2] * sinf(theta);
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z_angle = inImage[2] * cosf(theta) - inImage[1] * sinf(theta);
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/*if within the acceptance angle */
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/* if kfg is <0 then the pixel is outside of the key color */
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kfg = x_angle - (fabsf(z_angle) / tanf(acceptance / 2.f));
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if (kfg > 0.f) { /* found a pixel that is within key color */
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alpha = (1.f - kfg) * (gain);
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beta = atan2(z_angle, x_angle);
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/* if beta is within the cutoff angle */
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if (fabsf(beta) < (cutoff / 2.f)) {
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alpha = 0.f;
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}
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/* don't make something that was more transparent less transparent */
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if (alpha < inImage[3]) {
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output[0] = alpha;
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}
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else {
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output[0] = inImage[3];
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}
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}
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else { /*pixel is outside key color */
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output[0] = inImage[3]; /* make pixel just as transparent as it was before */
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}
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}
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