diff options
Diffstat (limited to 'source/blender/compositor/operations/COM_ChromaMatteOperation.cc')
-rw-r--r-- | source/blender/compositor/operations/COM_ChromaMatteOperation.cc | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/source/blender/compositor/operations/COM_ChromaMatteOperation.cc b/source/blender/compositor/operations/COM_ChromaMatteOperation.cc new file mode 100644 index 00000000000..52de0198a00 --- /dev/null +++ b/source/blender/compositor/operations/COM_ChromaMatteOperation.cc @@ -0,0 +1,109 @@ +/* + * 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_ChromaMatteOperation.h" +#include "BLI_math.h" + +ChromaMatteOperation::ChromaMatteOperation() +{ + addInputSocket(COM_DT_COLOR); + addInputSocket(COM_DT_COLOR); + addOutputSocket(COM_DT_VALUE); + + this->m_inputImageProgram = nullptr; + this->m_inputKeyProgram = nullptr; +} + +void ChromaMatteOperation::initExecution() +{ + this->m_inputImageProgram = this->getInputSocketReader(0); + this->m_inputKeyProgram = this->getInputSocketReader(1); +} + +void ChromaMatteOperation::deinitExecution() +{ + this->m_inputImageProgram = nullptr; + this->m_inputKeyProgram = nullptr; +} + +void ChromaMatteOperation::executePixelSampled(float output[4], + float x, + float y, + PixelSampler sampler) +{ + float inKey[4]; + float inImage[4]; + + const float acceptance = this->m_settings->t1; /* in radians */ + const float cutoff = this->m_settings->t2; /* in radians */ + const float gain = this->m_settings->fstrength; + + float x_angle, z_angle, alpha; + float theta, beta; + float kfg; + + this->m_inputKeyProgram->readSampled(inKey, x, y, sampler); + this->m_inputImageProgram->readSampled(inImage, x, y, sampler); + + /* Store matte(alpha) value in [0] to go with + * #COM_SetAlphaMultiplyOperation and the Value output. */ + + /* Algorithm from book "Video Demystified", does not include the spill reduction part. */ + /* Find theta, the angle that the color space should be rotated based on key. */ + + /* rescale to -1.0..1.0 */ + // inImage[0] = (inImage[0] * 2.0f) - 1.0f; // UNUSED + inImage[1] = (inImage[1] * 2.0f) - 1.0f; + inImage[2] = (inImage[2] * 2.0f) - 1.0f; + + // inKey[0] = (inKey[0] * 2.0f) - 1.0f; // UNUSED + inKey[1] = (inKey[1] * 2.0f) - 1.0f; + inKey[2] = (inKey[2] * 2.0f) - 1.0f; + + theta = atan2(inKey[2], inKey[1]); + + /*rotate the cb and cr into x/z space */ + x_angle = inImage[1] * cosf(theta) + inImage[2] * sinf(theta); + z_angle = inImage[2] * cosf(theta) - inImage[1] * sinf(theta); + + /*if within the acceptance angle */ + /* if kfg is <0 then the pixel is outside of the key color */ + kfg = x_angle - (fabsf(z_angle) / tanf(acceptance / 2.0f)); + + if (kfg > 0.0f) { /* found a pixel that is within key color */ + alpha = 1.0f - (kfg / gain); + + beta = atan2(z_angle, x_angle); + + /* if beta is within the cutoff angle */ + if (fabsf(beta) < (cutoff / 2.0f)) { + alpha = 0.0f; + } + + /* don't make something that was more transparent less transparent */ + if (alpha < inImage[3]) { + output[0] = alpha; + } + else { + output[0] = inImage[3]; + } + } + else { /*pixel is outside key color */ + output[0] = inImage[3]; /* make pixel just as transparent as it was before */ + } +} |