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
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
// Copyright (C) 2011 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_LABEL_CONNeCTED_BLOBS_H_
#define DLIB_LABEL_CONNeCTED_BLOBS_H_
#include "label_connected_blobs_abstract.h"
#include "../geometry.h"
#include <stack>
#include <vector>
namespace dlib
{
// ----------------------------------------------------------------------------------------
struct neighbors_8
{
void operator() (
const point& p,
std::vector<point>& neighbors
) const
{
neighbors.push_back(point(p.x()+1,p.y()+1));
neighbors.push_back(point(p.x()+1,p.y() ));
neighbors.push_back(point(p.x()+1,p.y()-1));
neighbors.push_back(point(p.x(),p.y()+1));
neighbors.push_back(point(p.x(),p.y()-1));
neighbors.push_back(point(p.x()-1,p.y()+1));
neighbors.push_back(point(p.x()-1,p.y() ));
neighbors.push_back(point(p.x()-1,p.y()-1));
}
};
struct neighbors_4
{
void operator() (
const point& p,
std::vector<point>& neighbors
) const
{
neighbors.push_back(point(p.x()+1,p.y()));
neighbors.push_back(point(p.x()-1,p.y()));
neighbors.push_back(point(p.x(),p.y()+1));
neighbors.push_back(point(p.x(),p.y()-1));
}
};
// ----------------------------------------------------------------------------------------
struct connected_if_both_not_zero
{
template <typename image_type>
bool operator() (
const image_type& img,
const point& a,
const point& b
) const
{
return (img[a.y()][a.x()] != 0 && img[b.y()][b.x()] != 0);
}
};
struct connected_if_equal
{
template <typename image_type>
bool operator() (
const image_type& img,
const point& a,
const point& b
) const
{
return (img[a.y()][a.x()] == img[b.y()][b.x()]);
}
};
// ----------------------------------------------------------------------------------------
struct zero_pixels_are_background
{
template <typename image_type>
bool operator() (
const image_type& img,
const point& p
) const
{
return img[p.y()][p.x()] == 0;
}
};
struct nothing_is_background
{
template <typename image_type>
bool operator() (
const image_type&,
const point&
) const
{
return false;
}
};
// ----------------------------------------------------------------------------------------
template <
typename image_type,
typename label_image_type,
typename background_functor_type,
typename neighbors_functor_type,
typename connected_functor_type
>
unsigned long label_connected_blobs (
const image_type& img_,
const background_functor_type& is_background,
const neighbors_functor_type& get_neighbors,
const connected_functor_type& is_connected,
label_image_type& label_img_
)
{
// make sure requires clause is not broken
DLIB_ASSERT(is_same_object(img_, label_img_) == false,
"\t unsigned long label_connected_blobs()"
<< "\n\t The input image and output label image can't be the same object."
);
const_image_view<image_type> img(img_);
image_view<label_image_type> label_img(label_img_);
std::stack<point> neighbors;
label_img.set_size(img.nr(), img.nc());
assign_all_pixels(label_img, 0);
unsigned long next = 1;
if (img.size() == 0)
return 0;
const rectangle area = get_rect(img);
std::vector<point> window;
for (long r = 0; r < img.nr(); ++r)
{
for (long c = 0; c < img.nc(); ++c)
{
// skip already labeled pixels or background pixels
if (label_img[r][c] != 0 || is_background(img,point(c,r)))
continue;
label_img[r][c] = next;
// label all the neighbors of this point
neighbors.push(point(c,r));
while (neighbors.size() > 0)
{
const point p = neighbors.top();
neighbors.pop();
window.clear();
get_neighbors(p, window);
for (unsigned long i = 0; i < window.size(); ++i)
{
if (area.contains(window[i]) && // point in image.
!is_background(img,window[i]) && // isn't background.
label_img[window[i].y()][window[i].x()] == 0 && // haven't already labeled it.
is_connected(img, p, window[i])) // it's connected.
{
label_img[window[i].y()][window[i].x()] = next;
neighbors.push(window[i]);
}
}
}
++next;
}
}
return next;
}
// ----------------------------------------------------------------------------------------
}
#endif // DLIB_LABEL_CONNeCTED_BLOBS_H_
|
