请看注释。这个函数,是人脸识别主函数,里面出现过的函数之一,作用是初始化分类器的数据,就是一个xml文件的数据初始化。
1 static CvHidHaarClassifierCascade* icvCreateHidHaarClassifierCascade( CvHaarClassifierCascade* cascade )
2 {
3 CvRect* ipp_features = 0;//定义一个矩形框指针
4 float *ipp_weights = 0, *ipp_thresholds = 0, *ipp_val1 = 0, *ipp_val2 = 0;//单精度浮点数指针4个
5 int* ipp_counts = 0;//整形指针1个
6
7 CvHidHaarClassifierCascade* out = 0;//最终返回的值
8
9 int i, j, k, l;//for循环的控制变量
10 int datasize;//数据大小
11 int total_classifiers = 0;//总的分类器数目
12 int total_nodes = 0;
13 char errorstr[1000];//错误信息数组
14 CvHidHaarClassifier* haar_classifier_ptr;//级联分类器指针
15 CvHidHaarTreeNode* haar_node_ptr;
16 CvSize orig_window_size;//提取窗口的大小
17 int has_tilted_features = 0;
18 int max_count = 0;
19
20 if( !CV_IS_HAAR_CLASSIFIER(cascade) )//判断传进来的分类器文件是否真正确
21 CV_Error( !cascade ? CV_StsNullPtr : CV_StsBadArg, "Invalid classifier pointer" );
22
23 if( cascade->hid_cascade )//判断改分类器xml文件是否已经被初始化了
24 CV_Error( CV_StsError, "hid_cascade has been already created" );
25
26 if( !cascade->stage_classifier )//如果没有阶级分类器,报错
27 CV_Error( CV_StsNullPtr, "" );
28
29 if( cascade->count <= 0 )//如果分类器的阶级数<=0,报错
30 CV_Error( CV_StsOutOfRange, "Negative number of cascade stages" );
31
32 orig_window_size = cascade->orig_window_size;//获取识别窗口的大小
33
34 /* check input structure correctness and calculate total memory size needed for
35 internal representation of the classifier cascade */
36
37 for( i = 0; i < cascade->count; i++ )//对xml文件里面的每阶段的stage进行循环提取相关数据
38 {
39 CvHaarStageClassifier* stage_classifier = cascade->stage_classifier + i;
40 //获取每次进入循环的后阶段的子分类器,以haarcascade_upperbody.xml 为例子,count是30,stage_classifier的count是20
41
42 if( !stage_classifier->classifier ||//判断阶段分类器、子分类器及其stage 层数 是否合法
43 stage_classifier->count <= 0 )
44 {
45 sprintf( errorstr, "header of the stage classifier #%d is invalid "
46 "(has null pointers or non-positive classfier count)", i );
47 CV_Error( CV_StsError, errorstr );
48 }
49
50 max_count = MAX( max_count, stage_classifier->count );//获取子分类器stage的数目,以haarcascade_upperbody.xml为例,是20
51 total_classifiers += stage_classifier->count;//统计出总的子分类器的stage数目,即tree,再统计
52
53 for( j = 0; j < stage_classifier->count; j++ )
54 //这个for循环主要是进入到子分类器tree里面的数据提取并且对其正确性的判断,
55 //循环条件为字stage数目,以haarcascade_upperbody.xml为例,为20
56 {
57 CvHaarClassifier* classifier = stage_classifier->classifier + j;//同上,找到此时循环的tree
58
59 total_nodes += classifier->count;//计算出此时循环的tree子分类器的root node 数目,再统计。以haarcascade_upperbody.xml为例,每个tree的node是1
60 for( l = 0; l < classifier->count; l++ )
61 //这个是关键循环,主数据的获取
62 //以haarcascade_upperbody.xml为例,此时classifier->count=1,循环一次,进入里面获取关键数据
63 {
64 for( k = 0; k < CV_HAAR_FEATURE_MAX; k++ )//CV_HAAR_FEATURE_MAX = 3,循环三次,feature的最大数目,以haarcascade_upperbody.xml为例,只有1个
65 {
66 if( classifier->haar_feature[l].rect[k].r.width )
67 //逐层递归,先找feature,再找它里面的rect标签里面的矩阵row,行的宽度
68 //以haarcascade_upperbody.xml为例,是2
69 {
70 CvRect r = classifier->haar_feature[l].rect[k].r;//把此时row矩阵框赋给r
71 int tilted = classifier->haar_feature[l].tilted;//获取xml标签tited的值
72 has_tilted_features |= tilted != 0;//|是位运算,例如0|1=1,这行的作用是判断has和tilted那个是1,还不知道其意义何在
73 if( r.width < 0 || r.height < 0 || r.y < 0 ||
74 r.x + r.width > orig_window_size.width
75 ||
76 (!tilted &&
77 (r.x < 0 || r.y + r.height > orig_window_size.height))
78 ||
79 (tilted && (r.x - r.height < 0 ||
80 r.y + r.width + r.height > orig_window_size.height)))
81 //这个if语句是对feature里面的数据矩形的各方面判断,包括矩形的宽、高、等
82 //矩形# %d的分类器# %d”“级分类器# %d是不是在里面”“参考(原创)级联窗口”
83 {
84 sprintf( errorstr, "rectangle #%d of the classifier #%d of "
85 "the stage classifier #%d is not inside "
86 "the reference (original) cascade window", k, j, i );
87 CV_Error( CV_StsNullPtr, errorstr );
88 }
89 }
90 }
91 }
92 }
93 }
94 //上面数据的判断结束后,到这里
95
96 datasize = sizeof(CvHidHaarClassifierCascade) +//获取整个分类器,xml文件的数据大小
97 sizeof(CvHidHaarStageClassifier)*cascade->count +
98 sizeof(CvHidHaarClassifier) * total_classifiers +
99 sizeof(CvHidHaarTreeNode) * total_nodes +
100 sizeof(void*)*(total_nodes + total_classifiers);
101
102 out = (CvHidHaarClassifierCascade*)cvAlloc( datasize );//给最终返回的变量分配内存大小
103 memset( out, 0, sizeof(*out) );//对变量初始化,全部填充0
104
105 //下面是逐个赋值,初始化头部
106 /* init header */
107 out->count = cascade->count;//新分类器out的stage数目
108 out->stage_classifier = (CvHidHaarStageClassifier*)(out + 1);//子分类器tree的数目
109 haar_classifier_ptr = (CvHidHaarClassifier*)(out->stage_classifier + cascade->count);//tree指针
110 haar_node_ptr = (CvHidHaarTreeNode*)(haar_classifier_ptr + total_classifiers);//tree里面node的指针
111
112 out->isStumpBased = 1;//布尔类型,true
113 out->has_tilted_features = has_tilted_features;
114 out->is_tree = 0;
115
116 /* initialize internal representation */
117 for( i = 0; i < cascade->count; i++ )
118 {
119 CvHaarStageClassifier* stage_classifier = cascade->stage_classifier + i;
120 CvHidHaarStageClassifier* hid_stage_classifier = out->stage_classifier + i;
121
122 hid_stage_classifier->count = stage_classifier->count;
123 hid_stage_classifier->threshold = stage_classifier->threshold - icv_stage_threshold_bias;
124 hid_stage_classifier->classifier = haar_classifier_ptr;
125 hid_stage_classifier->two_rects = 1;
126 haar_classifier_ptr += stage_classifier->count;
127
128 hid_stage_classifier->parent = (stage_classifier->parent == -1)
129 ? NULL : out->stage_classifier + stage_classifier->parent;
130 hid_stage_classifier->next = (stage_classifier->next == -1)
131 ? NULL : out->stage_classifier + stage_classifier->next;
132 hid_stage_classifier->child = (stage_classifier->child == -1)
133 ? NULL : out->stage_classifier + stage_classifier->child;
134
135 out->is_tree |= hid_stage_classifier->next != NULL;
136
137 for( j = 0; j < stage_classifier->count; j++ )
138 {
139 CvHaarClassifier* classifier = stage_classifier->classifier + j;
140 CvHidHaarClassifier* hid_classifier = hid_stage_classifier->classifier + j;
141 int node_count = classifier->count;
142 float* alpha_ptr = (float*)(haar_node_ptr + node_count);
143
144 hid_classifier->count = node_count;
145 hid_classifier->node = haar_node_ptr;
146 hid_classifier->alpha = alpha_ptr;
147
148 for( l = 0; l < node_count; l++ )
149 {
150 CvHidHaarTreeNode* node = hid_classifier->node + l;
151 CvHaarFeature* feature = classifier->haar_feature + l;
152 memset( node, -1, sizeof(*node) );
153 node->threshold = classifier->threshold[l];
154 node->left = classifier->left[l];
155 node->right = classifier->right[l];
156
157 if( fabs(feature->rect[2].weight) < DBL_EPSILON ||
158 feature->rect[2].r.width == 0 ||
159 feature->rect[2].r.height == 0 )
160 memset( &(node->feature.rect[2]), 0, sizeof(node->feature.rect[2]) );
161 else
162 hid_stage_classifier->two_rects = 0;
163 }
164
165 memcpy( alpha_ptr, classifier->alpha, (node_count+1)*sizeof(alpha_ptr[0]));
166 haar_node_ptr =
167 (CvHidHaarTreeNode*)cvAlignPtr(alpha_ptr+node_count+1, sizeof(void*));
168
169 out->isStumpBased &= node_count == 1;
170 }
171 }
172 /*
173 #ifdef HAVE_IPP
174 int can_use_ipp = !out->has_tilted_features && !out->is_tree && out->isStumpBased;
175
176 if( can_use_ipp )
177 {
178 int ipp_datasize = cascade->count*sizeof(out->ipp_stages[0]);
179 float ipp_weight_scale=(float)(1./((orig_window_size.width-icv_object_win_border*2)*
180 (orig_window_size.height-icv_object_win_border*2)));
181
182 out->ipp_stages = (void**)cvAlloc( ipp_datasize );
183 memset( out->ipp_stages, 0, ipp_datasize );
184
185 ipp_features = (CvRect*)cvAlloc( max_count*3*sizeof(ipp_features[0]) );
186 ipp_weights = (float*)cvAlloc( max_count*3*sizeof(ipp_weights[0]) );
187 ipp_thresholds = (float*)cvAlloc( max_count*sizeof(ipp_thresholds[0]) );
188 ipp_val1 = (float*)cvAlloc( max_count*sizeof(ipp_val1[0]) );
189 ipp_val2 = (float*)cvAlloc( max_count*sizeof(ipp_val2[0]) );
190 ipp_counts = (int*)cvAlloc( max_count*sizeof(ipp_counts[0]) );
191
192 for( i = 0; i < cascade->count; i++ )
193 {
194 CvHaarStageClassifier* stage_classifier = cascade->stage_classifier + i;
195 for( j = 0, k = 0; j < stage_classifier->count; j++ )
196 {
197 CvHaarClassifier* classifier = stage_classifier->classifier + j;
198 int rect_count = 2 + (classifier->haar_feature->rect[2].r.width != 0);
199
200 ipp_thresholds[j] = classifier->threshold[0];
201 ipp_val1[j] = classifier->alpha[0];
202 ipp_val2[j] = classifier->alpha[1];
203 ipp_counts[j] = rect_count;
204
205 for( l = 0; l < rect_count; l++, k++ )
206 {
207 ipp_features[k] = classifier->haar_feature->rect[l].r;
208 //ipp_features[k].y = orig_window_size.height - ipp_features[k].y - ipp_features[k].height;
209 ipp_weights[k] = classifier->haar_feature->rect[l].weight*ipp_weight_scale;
210 }
211 }
212
213 if( ippiHaarClassifierInitAlloc_32f( (IppiHaarClassifier_32f**)&out->ipp_stages[i],
214 (const IppiRect*)ipp_features, ipp_weights, ipp_thresholds,
215 ipp_val1, ipp_val2, ipp_counts, stage_classifier->count ) < 0 )
216 break;
217 }
218
219 if( i < cascade->count )
220 {
221 for( j = 0; j < i; j++ )
222 if( out->ipp_stages[i] )
223 ippiHaarClassifierFree_32f( (IppiHaarClassifier_32f*)out->ipp_stages[i] );
224 cvFree( &out->ipp_stages );
225 }
226 }
227 #endif
228 */
229 cascade->hid_cascade = out;
230 assert( (char*)haar_node_ptr - (char*)out <= datasize );
231
232 cvFree( &ipp_features );
233 cvFree( &ipp_weights );
234 cvFree( &ipp_thresholds );
235 cvFree( &ipp_val1 );
236 cvFree( &ipp_val2 );
237 cvFree( &ipp_counts );
238
239 return out;
240 }