dal forum utenti SIGE:
"these folder are created if the corresponding options are activated. If you use the watermark option, then the folder is generated and the watermark images are generated in this folder (the same thing with the resized folder). If you use the overwrite feature, then the images are created on every call, so you should use this feature only to create new images after you have changed some settings.
The dimensions are controlled by the selected box. Switch to the slimbox if you don't want the images to be resized. All other boxes resize the images to the browser window dimension".