Fixed issue where OMR input images are processed twice in Windows env…

[aqoshi]

This fixes the bug in #130 where images process twice due to Windows being case-insensitive.

131 makes a change that appears to be valid but project maintainer suggested a simpler approach (as implemented).

[Udayraj123]

Hi @aqoshi, I've approved the PR. If you may, you can add a screenshot of "Total count" in windows which also shows a folder with input images

[aqoshi]

Taken by my own input images: used 4, and 4 were processed. [Windows OS]