图像分类

def _interval_overlap(interval_a, interval_b): x1, x2 = interval_a x3, x4 = interval_b

if x3 < x1:
    if x4 < x1:
        return 0
    else:
        return min(x2, x4) - x1
else:
    if x2 < x3:
        return 0
    else:
        return min(x2, x4) - x3

def _sigmoid(x): return 1. / (1. + np.exp(-x))

def _bbox_iou(box1, box2): intersect_w = _interval_overlap([box1.xmin, box1.xmax], [box2.xmin, box2.xmax]) intersect_h = _interval_overlap([box1.ymin, box1.ymax], [box2.ymin, box2.ymax]) intersect = intersect_w * intersect_h

w1, h1 = box1.xmax - box1.xmin, box1.ymax - box1.ymin
w2, h2 = box2.xmax - box2.xmin, box2.ymax - box2.ymin

union = w1 * h1 + w2 * h2 - intersect

return float(intersect) / union