Fix image reading on camvid

[pantment]

I encountered inconsistencies in image dimensions when using the PIL library, likely due to differences in image formats (e.g., JPG vs. PNG). Some images and labels were read as width, height, while others were interpreted as height, width, leading to confusion. Additionally, the behavior of the resize function made it harder to pinpoint the issue. After switching to OpenCV (cv2), these inconsistencies were resolved.