Image(Numpy, Opencv) To Tensor

def img2tensor(img):
    #the format of img needs to be bgr format

    img = img[..., ::-1]  #bgr2rgb
    img = img.transpose(2, 0, 1)  #(H, W, CH) -> (CH, H, W)
    img = np.ascontiguousarray(img)
    
    tensor = torch.tensor(img, dtype=torch.float32)
    return tensor