If you edit some images with your default image-viewer and when you will save it, image-viewer will ask you to give name, and if in directory is file with the same name, the suggest name will be /filename/ (1).jpg with space between filename and (1). Open any image from DCIM in image-viewer and click "save as" and wait a second and you will see

OK I found solution, app will be making thumbs for files with space in name, I will code this maeby today