class_docstr: Args:
      input_shape (int): network input image size
      ori_shape (int): ori image shape of before padding
      scale_factor (float): scale factor of ori image
      enable_mkldnn (bool): whether to open MKLDNN
code: def img_info(self, ori_img, img):
      origin_shape = ori_img.shape
      resize_shape = img.shape
      im_scale_y = resize_shape[2] / float(origin_shape[0])
      im_scale_x = resize_shape[3] / float(origin_shape[1])
      scale_factor = np.array(
          [im_scale_y, im_scale_x], dtype=np.float32
      )
      img_shape = np.array(img.shape[2:], dtype=np.float32)
  
      input_shape = np.array(img).astype("float32").shape[2:]
      ori_shape = np.array((img_shape,)).astype("float32")
      scale_factor = np.array((scale_factor,)).astype("float32")
      return ori_shape, input_shape, scale_factor
  
file_path: PaddleOCR/ppocr/postprocess/picodet_postprocess.py
imports: import numpy
  from scipy.special import softmax
label_desc: Use image node_id 4 for calling the PicoDetPostProcess obj's underlying member method code with example usage: obj.img_info(ori_img, img) and returns: ori_shape,  input_shape,  scale_factor