Extract same number of regions.

[chrisrn]

Can I extract exactly 20 bounding boxes for every image? I changed the scale parameter but the number of bounding boxes differs between different images.

[UpCoder]

Did you solved the problem? I also want to determine the number of bounding box.

[sdadia]

• You cannot control the exact number of extracted box directly.

• But you can just select top 20 boxes using :

top_20_boxes = regions[0:20]

• But you can just select top N boxes using :

top_N_boxes = regions[0:N]

[UpCoder]

Thanks for replying. I am reading the paper R-CNN, In this paper, the author said they extract 2000 region from every picture. They also using selective region method to extract region. So I feel confused, I thought the selective region method can control the number of bounding box.

[sdadia]

The selective search algorithm does not permit exact control of boxes (read the original selective search paper) nor any variants of selective search.

The R-CNN authors first do non-maxima suppression and then simply just pick top 2000 boxes. This leads to boxes which are non-overlapping and boxes are spread around the whole image minimizing the chance to missed an object.

[UpCoder]

em, I will continue to understand this paper, I not yet totally understand that. Thank you very much.