Multiple bounding box for same object

[iamrajee]

I'm getting multiple bounding box for same object using yolov4 with default parameters, cfg and weights. I tried increasing beta_nms and decreaseing iou_thresh to extreme in yolov4.cfg but no luck.

I will really appreciate any help.

[bulatnv]

@iamrajee

This is because Intersection over Union btw aeroplane 0.97 and 0.67 is small. First object is big, second is pretty small. As a result IoU < 0.4. You can try eliminating this double detections by calculating Intersection over Area of first and second detections.

All the best.

[iamrajee]

Thank you for your suggestion, I implemented NMS Algorithem on top of yolo bounding boxes and it worked. However I don't know why I couldn't get the similar result by modifying the in-build parameter in yolov4.cfg. I even set the 'iou_thresh' as low as 0.05 and beta_nms as high as 0.9 still no effect. Is there any other parameter that might affect this behaviour?

[bulatnv]

@iamrajee This parameters for model train, not for prediction: https://github.com/AlexeyAB/darknet/wiki/CFG-Parameters-in-the-different-layers

[iamrajee]

Thank so much @bulatnv for the guidance. I will go through this and get back if I have any further queries.

[tarun-ssharma]

Hi @iamrajee . Did you refer any tutorial while writing custom NMS on top of darknet detector output? Can you share any reference?

I am facing the same issue of multiple bounding boxes. In some case, the bounding boxes are not even placed properly on the detected object.

[elize-anu]

@iamrajee Hi, Can you please provide the NMS algo which you've implemented over the yolo bounding boxes. I'm also facing the same multiple bounding boxes issue for yolo v4

[iamrajee]

@tarun-ssharma @elize-anu I had refered NMS code from here and this is how I had integrated into my code.