Selector "Convert image format" supports two modes: "From JPG to BMP" and "From BMP to JPG".
1. Check box "Ask for a source folder".
If this checkbox selected then program will ask user to define a sorce folder containing photos to shrink.
If the checkbox deselected then request for the source folder will be skipped and program will select automatically the last processed folder.
2. Selector "Convert image format" supports the following image formats: JPG, BMP, GIF, TIF.