utils.py

# coding=utf-8


def IntersectBBox(bbox1, bbox2):
    intersect_bbox = []
    if bbox2[0] >= bbox1[2] or bbox2[2] <= bbox1[0] or bbox2[1] >= bbox1[3] or bbox2[3] <= bbox1[1]:
        # return [0, 0, 0, 0], if there is no intersection
        return intersect_bbox
    else:
        intersect_bbox.append([max(bbox1[0], bbox2[0]), max(bbox1[1], bbox2[1]),
                               min(bbox1[2], bbox2[2]), min(bbox1[3], bbox2[3])])
    return intersect_bbox


def JaccardOverlap(bbox1, bbox2):
    intersect_bbox = IntersectBBox(bbox1, bbox2)
    if len(intersect_bbox) == 0:
        return 0
    else:
        intersect_width = int(intersect_bbox[0][2]) - int(intersect_bbox[0][0])
        intersect_height = int(intersect_bbox[0][3]) - int(intersect_bbox[0][1])
        if intersect_width and intersect_height > 0:
            intersect_size = float(intersect_width) * float(intersect_height)
            bbox1_size = float(bbox1[3] - bbox1[1]) * float(bbox1[2] - bbox1[0])
            bbox2_size = float(bbox2[3] - bbox2[1]) * float(bbox2[2] - bbox2[0])
            return float(intersect_size / float(bbox1_size + bbox2_size - intersect_size))
        else:
            return 0