Hi all,
I've figured out why the contours decrease when the image resolution is reduced. The reason is due to image interpolation.
If cv2.resize was used, there is a argument for the type of interpolation to be used:
interpolation method:
- INTER_NEAREST - a nearest-neighbor interpolation
- INTER_LINEAR - a bilinear interpolation (used by default)
- INTER_AREA - resampling using pixel area relation. It may be a preferred method for image decimation,
as it gives moire’-free results. But when the image is zoomed, it is similar to the INTER_NEAREST method.
- INTER_CUBIC - a bicubic interpolation over 4x4 pixel neighborhood
- INTER_LANCZOS4 - a Lanczos interpolation over 8x8 pixel neighborhood
