util.py 文件源码

def batch_iou(boxes, box):
  """Compute the Intersection-Over-Union of a batch of boxes with another
  box.

  Args:
    box1: 2D array of [cx, cy, width, height].
    box2: a single array of [cx, cy, width, height]
  Returns:
    ious: array of a float number in range [0, 1].
  """
  lr = np.maximum(
      np.minimum(boxes[:,0]+0.5*boxes[:,2], box[0]+0.5*box[2]) - \
      np.maximum(boxes[:,0]-0.5*boxes[:,2], box[0]-0.5*box[2]),
      0
  )
  tb = np.maximum(
      np.minimum(boxes[:,1]+0.5*boxes[:,3], box[1]+0.5*box[3]) - \
      np.maximum(boxes[:,1]-0.5*boxes[:,3], box[1]-0.5*box[3]),
      0
  )
  inter = lr*tb
  union = boxes[:,2]*boxes[:,3] + box[2]*box[3] - inter
  return inter/union