Detector's detect() method returns nothing

[alexyuisme]

Hello,

I got yolo_cpp_dll compiled and work but the Detector failed to detect objects from an image:

std::string file_name = "C:\person.jpg";
std::vector<bbox_t> boxes;
boxes = detector->detect(file_name); // ---> boxes.size() is 0.

But It works if I run the command line to test the same image.

.\darknet detect cfg/yolov4.cfg yolov4.weights data/person.jpg

Any possible reasons?

Thanks,
Alex

[alexyuisme]

Tracing down the problem from the source, the issue is l.output[obj_index] == nan for all three yolo layers.

int yolo_num_detections(layer l, float thresh)
{
int i, n;
int count = 0;
for(n = 0; n < l.n; ++n){
for (i = 0; i < l.wl.h; ++i) {
int obj_index = entry_index(l, 0, nl.w*l.h + i, 4);
if(l.output[obj_index] > thresh){ // -----> l.output[obj_index] == nan !!
++count;
}
}
}
return count;
}

[alexyuisme]

fix is found: one needs to remove CUDNN_HALF pre-compile flag before compiling yolo_cpp_dll.

[CemEntok]

Hey @alexyuisme

• Why do you need compiling yolo_cpp_dll?
• Did you also try this and make this worked?
  ./darknet detector test obj.data yolov4-obj.cfg yolov4-obj_best.weights -ext_output -dont_show < test.txt > result.txt