When searching for images to fit some predefined web or document layout, it'll often be important to consider their aspect ratio. But that can require some manual calculations, particularly if your images aren't in standard sizes (800x600, 640x480 etc).

Arti is a free, portable tool which can calculate and list the aspect ratios for any set of images, making it much easier to find whatever you need.

The program has options to add selected files or entire folders, or you can drag and drop your target images onto the Arti window. A table then lists their names, widths and heights, their exact ratio (4:3), the decimal equivalent (1.33), or the nearest match to a list of preset ratios (handy if you'd like something at 16:9, say, but don't mind if it's a few pixels out).

Double-clicking a suitable image opens it in your default viewer, and if you're happy then you can open its containing folder for further processing.

Alternatively, Arti's report may be saved as a CSV file for reference later.

Version 1.0.3 brings (Changelog):
    + While a scan is in progress, the menu bar will reduce to a single Cancel menu with a Cancel option.  You can also cancel by pressing the Escape key while a scan is in progress.
    + Added an option to enable/disable recursive scanning.