Fawkes API  Fawkes Development Version
difference.cpp
1 
2 /***************************************************************************
3  * difference.cpp - implementation of difference intensity filter
4  *
5  * Created: Sun Jun 25 23:07:35 2006 (on train to Ac, father in hospital)
6  * Copyright 2005-2007 Tim Niemueller [www.niemueller.de]
7  *
8  ****************************************************************************/
9 
10 /* This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version. A runtime exception applies to
14  * this software (see LICENSE.GPL_WRE file mentioned below for details).
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19  * GNU Library General Public License for more details.
20  *
21  * Read the full text in the LICENSE.GPL_WRE file in the doc directory.
22  */
23 
24 #include <fvfilters/difference.h>
25 #include <fvutils/color/yuv.h>
26 
27 #include <cstddef>
28 
29 namespace firevision {
30 
31 /** @class FilterDifference <fvfilters/difference.h>
32  * Calculates the difference of two images.
33  */
34 
35 /** Constructor. */
36 FilterDifference::FilterDifference() : Filter("FilterDifference", 2)
37 {
38 }
39 
40 void
42 {
43  if (src[0] == NULL)
44  return;
45  if (src[1] == NULL)
46  return;
47  if (src_roi[0] == NULL)
48  return;
49  if (src_roi[1] == NULL)
50  return;
51 
52  unsigned int h = 0;
53  unsigned int w = 0;
54 
55  // y-plane
56  unsigned char *byp = src[0] + (src_roi[0]->start.y * src_roi[0]->line_step)
57  + (src_roi[0]->start.x * src_roi[0]->pixel_step);
58  // u-plane
59  unsigned char *bup =
60  YUV422_PLANAR_U_PLANE(src[0], src_roi[0]->image_width, src_roi[0]->image_height)
61  + ((src_roi[0]->start.y * src_roi[0]->line_step) / 2
62  + (src_roi[0]->start.x * src_roi[0]->pixel_step) / 2);
63  // v-plane
64  unsigned char *bvp =
65  YUV422_PLANAR_V_PLANE(src[0], src_roi[0]->image_width, src_roi[0]->image_height)
66  + ((src_roi[0]->start.y * src_roi[0]->line_step) / 2
67  + (src_roi[0]->start.x * src_roi[0]->pixel_step) / 2);
68 
69  // y-plane
70  unsigned char *fyp = src[1] + (src_roi[1]->start.y * src_roi[1]->line_step)
71  + (src_roi[1]->start.x * src_roi[1]->pixel_step);
72  // u-plane
73  unsigned char *fup =
74  YUV422_PLANAR_U_PLANE(src[1], src_roi[1]->image_width, src_roi[1]->image_height)
75  + ((src_roi[1]->start.y * src_roi[1]->line_step) / 2
76  + (src_roi[1]->start.x * src_roi[1]->pixel_step) / 2);
77  // v-plane
78  unsigned char *fvp =
79  YUV422_PLANAR_V_PLANE(src[1], src_roi[1]->image_width, src_roi[1]->image_height)
80  + ((src_roi[1]->start.y * src_roi[1]->line_step) / 2
81  + (src_roi[1]->start.x * src_roi[1]->pixel_step) / 2);
82 
83  // destination y-plane
84  unsigned char *dyp =
86  // destination u-plane
87  unsigned char *dup =
88  YUV422_PLANAR_U_PLANE(dst, dst_roi->image_width, dst_roi->image_height)
89  + ((dst_roi->start.y * dst_roi->line_step) / 2 + (dst_roi->start.x * dst_roi->pixel_step) / 2);
90  // destination v-plane
91  unsigned char *dvp =
92  YUV422_PLANAR_V_PLANE(dst, dst_roi->image_width, dst_roi->image_height)
93  + ((dst_roi->start.y * dst_roi->line_step) / 2 + (dst_roi->start.x * dst_roi->pixel_step) / 2);
94 
95  // line starts
96  unsigned char *lbyp = byp; // y-plane
97  unsigned char *lbup = fup; // u-plane
98  unsigned char *lbvp = fvp; // v-plane
99  unsigned char *lfyp = fyp; // y-plane
100  unsigned char *lfup = fup; // u-plane
101  unsigned char *lfvp = fvp; // v-plane
102  unsigned char *ldyp = dyp; // destination y-plane
103  unsigned char *ldup = dup; // destination u-plane
104  unsigned char *ldvp = dvp; // destination v-plane
105 
106  for (h = 0; (h < src_roi[1]->height) && (h < dst_roi->height); ++h) {
107  for (w = 0; (w < src_roi[1]->width) && (w < dst_roi->width); w += 2) {
108  *dyp++ = ((*byp - *fyp) < 0) ? 0 : (*byp - *fyp);
109  ++byp;
110  ++fyp;
111  *dyp++ = ((*byp - *fyp) < 0) ? 0 : (*byp - *fyp);
112  ++byp;
113  ++fyp;
114 
115  *dup++ = (*fup++ + *bup++) / 2;
116  *dvp++ = (*fvp++ + *bvp++) / 2;
117  }
118 
119  lbyp += src_roi[0]->line_step;
120  lbup += src_roi[0]->line_step / 2;
121  lbvp += src_roi[0]->line_step / 2;
122  lfyp += src_roi[1]->line_step;
123  lfup += src_roi[1]->line_step / 2;
124  lfvp += src_roi[1]->line_step / 2;
125  ldyp += dst_roi->line_step;
126  ldup += dst_roi->line_step / 2;
127  ldvp += dst_roi->line_step / 2;
128  byp = lbyp;
129  bup = lbup;
130  bvp = lbvp;
131  fyp = lfyp;
132  fup = lfup;
133  fvp = lfvp;
134  dyp = ldyp;
135  dup = ldup;
136  dvp = ldvp;
137  }
138 }
139 
140 } // end namespace firevision
FilterDifference()
Constructor.
Definition: difference.cpp:36
virtual void apply()
Apply the filter.
Definition: difference.cpp:41
Filter interface.
Definition: filter.h:33
ROI ** src_roi
Source ROIs, dynamically allocated by Filter ctor.
Definition: filter.h:66
unsigned char ** src
Source buffers, dynamically allocated by Filter ctor.
Definition: filter.h:61
unsigned char * dst
Destination buffer.
Definition: filter.h:63
ROI * dst_roi
Destination ROI.
Definition: filter.h:68
unsigned int height
ROI height.
Definition: roi.h:119
fawkes::upoint_t start
ROI start.
Definition: roi.h:115
unsigned int line_step
line step
Definition: roi.h:125
unsigned int width
ROI width.
Definition: roi.h:117
unsigned int image_width
width of image that contains this ROI
Definition: roi.h:121
unsigned int pixel_step
pixel step
Definition: roi.h:127
unsigned int image_height
height of image that contains this ROI
Definition: roi.h:123
unsigned int x
x coordinate
Definition: types.h:36
unsigned int y
y coordinate
Definition: types.h:37