From Bruno Cancellieri:
Pictoscope has all you need to enjoy your digital images in various comfortable ways. It can display images in four different forms:
Normal: the image is contained in a normal window, with borders and clip controls. It is displayed in the original format if it fits in the screen, otherwise it is automatically reduced to the maximum size fitting in the screen. You can then optionally crop or resize the image by dragging the windows borders or the image itself, hide the borders and even set the image in a slow and random motion. The cropped or resized image can be saved in JPEG format with selectable quality level, with original resolution or with the resolution seen on the screen.
Full screen: the image is shown in the middle of the screen, on a black background that fills the rest of screen, hiding anything else. You can pass from normal view to full screen view and vice versa by double clicking the image
Slide show, with an optional, barely noticeable status bar showing various indicators, including the number of images unseen compared with the total number of pictures. You can crop and/or resize pictures on the fly, using the built-in editing functionality or calling a predefined external editor without breaking the slide show sequence. The modified image will automatically replace the current image in the slide show. You can suspend a slide show, quit the program and resume the show another time exactly from the point of suspension (this sort of hibernation is especially useful when viewing shows with hundreds of pictures). Slide show scripts can be created automatically with a key stroke from the normal view of any picture and include all pictures in the same folder and, optionally, also those contained in all subfolders.
Thumbnails: You can also search pictures based on character strings to be found in names of image files contained in a folder or folder tree. You can run slide shows or thumbnails with the search results.