iou 为面积的交并比，在目标检测中非常常见，英文为 Intersection-over-Union。
图示:
计算格式:
python 代码:
class IOU: def calc_iou(self, bbox1, bbox2): """ calc iou :param bbox1: (x1,y1,x2,y2) :param bbox2: (x1,y1,x2,y2) :return: """ w_1 = abs(bbox1[0] - bbox1[2]) h_1 = abs(bbox1[1] - bbox1[3]) area_1 = w_1 * h_1 w_2 = abs(bbox2[0] - bbox2[2]) h_2 = abs(bbox2[1] - bbox2[3]) area_2 = w_2 * h_2 min_x_1 = min(bbox1[0], bbox1[2]) min_y_1 = min(bbox1[1], bbox1[3]) max_x_1 = max(bbox1[0], bbox1[2]) max_y_1 = max(bbox1[1], bbox1[3]) min_x_2 = min(bbox2[0], bbox2[2]) min_y_2 = min(bbox2[1], bbox2[3]) max_x_2 = max(bbox2[0], bbox2[2]) max_y_2 = max(bbox2[1], bbox2[3]) overlap_min_x = max(min_x_1, min_x_2) overlap_min_y = max(min_y_1, min_y_2) overlap_max_x = min(max_x_1, max_x_2) overlap_max_y = min(max_y_1, max_y_2) overlap_w = max(0, overlap_max_x - overlap_min_x) overlap_h = max(0, overlap_max_y - overlap_min_y) overlap_area = overlap_w * overlap_h iou = overlap_area / (area_1 + area_2 - overlap_area) return iou