About dataset synthesis

[YYwantPY]

Hello:
In the json file of the training dataset,the values of the parameters "motion_amount" and "center" are float point. How do you paste foreground objects to background image while pixel position is int point? The paper mentioned that you reconstructed the image in continious domain with bicubic interpolation method. Do you enlarge the image first using bicubic interpolation method ?And then paste the foreground objects and dowmsample the image synthesized. Can you tell me the process of the reconstruction ?