1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
|
/*
* Copyright 2011, Blender Foundation.
*
* 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.
*
* Contributor:
* Dalai Felinto
*/
#include "COM_ChromaMatteOperation.h"
#include "BLI_math.h"
ChromaMatteOperation::ChromaMatteOperation() : NodeOperation()
{
addInputSocket(COM_DT_COLOR);
addInputSocket(COM_DT_COLOR);
addOutputSocket(COM_DT_VALUE);
this->m_inputImageProgram = NULL;
this->m_inputKeyProgram = NULL;
}
void ChromaMatteOperation::initExecution()
{
this->m_inputImageProgram = this->getInputSocketReader(0);
this->m_inputKeyProgram = this->getInputSocketReader(1);
}
void ChromaMatteOperation::deinitExecution()
{
this->m_inputImageProgram = NULL;
this->m_inputKeyProgram = NULL;
}
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_SetAlphaOperation and the Value output
*/
/* Algorithm from book "Video Demistified," 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.f));
if (kfg > 0.f) { /* 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.f)) {
alpha = 0.f;
}
/* 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 */
}
}
|
