在examples/darknet.c文件中若使用detect命令可以看到調用了test_detector.
...
else if (0 == strcmp(argv[1], "detect")){
float thresh = find_float_arg(argc, argv, "-thresh", .24);
char *filename = (argc > 4) ? argv[4]: 0;
char *outfile = find_char_arg(argc, argv, "-out", 0);
int fullscreen = find_arg(argc, argv, "-fullscreen");
test_detector("cfg/coco.data", argv[2], argv[3], filename, thresh, .5, outfile, fullscreen);
}
...
test_detector位於examples/detector.c :562,對其識別結果調用了draw_detections，在入口
void draw_detections(image im, detection *dets, int num, float thresh, char **names, image **alphabet, int classes)
中，存儲了識別結果的是dets，識別數量為num.
dets結構為：
typedef struct detection{
box bbox;
int classes;
float *prob;
float *mask;
float objectness;
int sort_class;
} detection;
box 結構為：
typedef struct{
float x, y, w, h;
} box;
那是不是直接使用如下的訪問方式就行了呢？
printf("x=%lf,y=%lf,w=%lf,h=%lf",
dets->bbox.x,dets->bbox.y,
dets->bbox.w,dets->bbox.h);
但是運行結果並不如意
x=0.324301,y=0.611036,w=0.313848,h=0.573097
其實獲取正確的矩形數據應該在draw_detections里尋找才是，果不其然，bingo！
void draw_detections(image im, detection *dets, int num, float thresh, char **names, image **alphabet, int classes)
{
...
for(i = 0; i < num; ++i){
...
int left = (b.x-b.w/2.)*im.w;
int right = (b.x+b.w/2.)*im.w;
int top = (b.y-b.h/2.)*im.h;
int bot = (b.y+b.h/2.)*im.h;
if(left < 0) left = 0;
if(right > im.w-1) right = im.w-1;
if(top < 0) top = 0;
if(bot > im.h-1) bot = im.h-1;
// add
printf("left=%d,right=%d,top=%d,bot=%d\n",left,right,top,bot);
// end add
...
}
將其在test_detector中嵌入，運行效果如下：
left=128,right=369,top=186,bot=517
left=533,right=621,top=94,bot=157
left=465,right=679,top=71,bot=169
left=205,right=576,top=151,bot=449
___________________________
(left,top)-----------
| |
| |
---------------(right,bot)
>[1] box,detection的定義在include\darknet.h >[2] detector.c在examples\detector.c >[3] image.c在src\image.c