Help to understand logic inside the evaluation loop

[veriff-javiervgd]

Hi I was looking at this code and I have a couple of questions to understand the logic behind this loop.

        for i in pbar:
            pbar.set_description('Processing {}'.format(settings[setting_id]))
            event_name = str(event_list[i][0][0])
            img_list = file_list[i][0]
            pred_list = pred[event_name]
            sub_gt_list = gt_list[i][0]
            # img_pr_info_list = np.zeros((len(img_list), thresh_num, 2))
            gt_bbx_list = facebox_list[i][0]

            for j in range(len(img_list)):
                pred_info = pred_list[str(img_list[j][0][0])]

                gt_boxes = gt_bbx_list[j][0].astype('float')
                keep_index = sub_gt_list[j][0]
                count_face += len(keep_index)

                if len(gt_boxes) == 0 or len(pred_info) == 0:
                    continue
                ignore = np.zeros(gt_boxes.shape[0])
                if len(keep_index) != 0:
                    ignore[keep_index-1] = 1
                pred_recall, proposal_list = image_eval(pred_info, gt_boxes, ignore, iou_thresh)

                _img_pr_info = img_pr_info(thresh_num, pred_info, proposal_list, pred_recall)

• What does sub_gt_list variable represent?
• What it keep_index and what is for? I understand it is used to count faces in count_face but at the same time to ignore them in ignore[keep_index-1] = 1, what is the logic behind this?
• Why pred_recall is the cumulative sum of all the ground truth boxes in order?