1 /*
2 * feature_match.cpp - optical flow feature match
3 *
4 * Copyright (c) 2016-2017 Intel Corporation
5 *
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 *
18 * Author: Wind Yuan <feng.yuan@intel.com>
19 * Author: Yinhang Liu <yinhangx.liu@intel.com>
20 */
21
22 #include "feature_match.h"
23
24 #define XCAM_FM_DEBUG 0
25
26 namespace XCam {
27
FeatureMatch()28 FeatureMatch::FeatureMatch ()
29 : _x_offset (0.0f)
30 , _mean_offset (0.0f)
31 , _valid_count (0)
32 , _fm_idx (-1)
33 , _frame_num (0)
34 {
35 }
36
37 void
set_config(CVFMConfig config)38 FeatureMatch::set_config (CVFMConfig config)
39 {
40 _config = config;
41 }
42
43 CVFMConfig
get_config()44 FeatureMatch::get_config ()
45 {
46 return _config;
47 }
48
49 void
set_fm_index(int idx)50 FeatureMatch::set_fm_index (int idx)
51 {
52 _fm_idx = idx;
53 }
54
55 void
reset_offsets()56 FeatureMatch::reset_offsets ()
57 {
58 _x_offset = 0.0f;
59 _mean_offset = 0.0f;
60 }
61
62 bool
get_mean_offset(std::vector<float> & offsets,float sum,int & count,float & mean_offset)63 FeatureMatch::get_mean_offset (std::vector<float> &offsets, float sum, int &count, float &mean_offset)
64 {
65 if (count < _config.min_corners)
66 return false;
67
68 mean_offset = sum / count;
69
70 #if XCAM_FM_DEBUG
71 XCAM_LOG_INFO (
72 "FeatureMatch(idx:%d): X-axis mean offset:%.2f, pre_mean_offset:%.2f (%d times, count:%d)",
73 _fm_idx, mean_offset, 0.0f, 0, count);
74 #endif
75
76 bool ret = true;
77 float delta = 20.0f;//mean_offset;
78 float pre_mean_offset = mean_offset;
79 for (int try_times = 1; try_times < 4; ++try_times) {
80 int recur_count = 0;
81 sum = 0.0f;
82
83 for (size_t i = 0; i < offsets.size (); ++i) {
84 if (fabs (offsets[i] - mean_offset) >= _config.recur_offset_error)
85 continue;
86 sum += offsets[i];
87 ++recur_count;
88 }
89
90 if (recur_count < _config.min_corners) {
91 ret = false;
92 break;
93 }
94
95 mean_offset = sum / recur_count;
96 #if XCAM_FM_DEBUG
97 XCAM_LOG_INFO (
98 "FeatureMatch(idx:%d): X-axis mean_offset:%.2f, pre_mean_offset:%.2f (%d times, count:%d)",
99 _fm_idx, mean_offset, pre_mean_offset, try_times, recur_count);
100 #endif
101
102 if (mean_offset == pre_mean_offset && recur_count == count)
103 return true;
104
105 if (fabs (mean_offset - pre_mean_offset) > fabs (delta) * 1.2f) {
106 ret = false;
107 break;
108 }
109
110 delta = mean_offset - pre_mean_offset;
111 pre_mean_offset = mean_offset;
112 count = recur_count;
113 }
114
115 return ret;
116 }
117
118 void
adjust_stitch_area(int dst_width,float & x_offset,Rect & stitch0,Rect & stitch1)119 FeatureMatch::adjust_stitch_area (int dst_width, float &x_offset, Rect &stitch0, Rect &stitch1)
120 {
121 if (fabs (x_offset) < 5.0f)
122 return;
123
124 int last_overlap_width = stitch1.pos_x + stitch1.width + (dst_width - (stitch0.pos_x + stitch0.width));
125 // int final_overlap_width = stitch1.pos_x + stitch1.width + (dst_width - (stitch0.pos_x - x_offset + stitch0.width));
126 if ((stitch0.pos_x - x_offset + stitch0.width) > dst_width)
127 x_offset = dst_width - (stitch0.pos_x + stitch0.width);
128 int final_overlap_width = last_overlap_width + x_offset;
129 final_overlap_width = XCAM_ALIGN_AROUND (final_overlap_width, 8);
130 XCAM_ASSERT (final_overlap_width >= _config.sitch_min_width);
131 int center = final_overlap_width / 2;
132 XCAM_ASSERT (center >= _config.sitch_min_width / 2);
133
134 stitch1.pos_x = XCAM_ALIGN_AROUND (center - _config.sitch_min_width / 2, 8);
135 stitch1.width = _config.sitch_min_width;
136 stitch0.pos_x = dst_width - final_overlap_width + stitch1.pos_x;
137 stitch0.width = _config.sitch_min_width;
138
139 float delta_offset = final_overlap_width - last_overlap_width;
140 x_offset -= delta_offset;
141 }
142
143 }
144