About this fork

This is a fork of ruotianluo/pytorch-faster-rcnn with a simplified script to extract boxes, scores, nms keep ids, and features from any set of images and dump them in a directory. Here I will just describe the additions I made to the original repository. For installation instructions please refer to the ORIGINAL_README.md.

What's new?

The following python script has been added:

tools/extract_boxes_scores_features.py

The python script allows you to easily extract detected bounding boxes, object class scores, nms keep ids, and the last layer features that may then be used in a downstream application. The script takes in a single argument im_in_out_json. This is the path to a json file that specifies the paths to the images on which you want to run the object detector and the directory where you want the outputs to be saved.

Structure of the im_in_out.json file

I created this repository for a project that needed object detection outputs on the HICO-Det dataset. So here's a sample of what the .json file actually looked like:

[
    {
        "in_path": "/home/ssd/hico_det_clean_20160224/images/train2015/HICO_train2015_00000001.jpg",
        "out_dir": "/home/ssd/hico_det_processed_20160224/faster_rcnn_boxes",
        "prefix": "HICO_train2015_00000001_"
    },
    {
        "in_path": "/home/ssd/hico_det_clean_20160224/images/train2015/HICO_train2015_00000002.jpg",
        "out_dir": "/home/ssd/hico_det_processed_20160224/faster_rcnn_boxes",
        "prefix": "HICO_train2015_00000002_"
    },
    {
        "in_path": "/home/ssd/hico_det_clean_20160224/images/train2015/HICO_train2015_00000003.jpg",
        "out_dir": "/home/ssd/hico_det_processed_20160224/faster_rcnn_boxes",
        "prefix": "HICO_train2015_00000003_"
    },
    ...
]

Essentially this is a list of dictionaries saved to a json file. Each dictionary specifies the following:

• in_path: path to the input image
• out_dir: directory where the extracted boxes, scores, nms ids, and features will be saved
• prefix: this specifies any prefix to be added to the filename while writing extracted data to out_dir

Sample output

When executed, for the first image we would see the following files written to out_dir:

• HICO_train2015_00000001_scores.npy (<prefix>scores.npy)
• HICO_train2015_00000001_boxes.npy (<prefix>boxes.npy)
• HICO_train2015_00000001_fc7.npy (<prefix>fc7.npy)
• HICO_train2015_00000001_nms_keep_indices.npy (<prefix>nms_keep_indices.npy)

How to Run

Assuming you have a trained model checkpoint and im_in_out.json file available:

• Update variable saved_model_path in extract_boxes_scores_features.py file to point to the checkpoint location
• Make sure the correct network architecture is being instantiated in line 133. Defaults to Resnet-152
• Run extraction as follows:

  python -m tools.extract_boxes_scores_features --im_in_out_json <path to im_in_out.json>