Radical Image Optimization Tool or RIOT, is a free Image optimizer which offers a wide range of features and tools for image resampling while a staunch compression tool is included to compress image files. Its main usability revolves around optimizing images, you can adjust compression parameters according to your needs, edit image meta information and change image masking (offers basic transparency threshold, and let user blend image with solid background). To bring ease in manipulating images, it offers multiple re-sampling filters having different attributes, some of which are; Bilinear, Catmul Rom, B-spline, and lot more.
Whilst supporting simple drag & drag behavior, it allows user to apply batch re-sampling over images. The main interface has two panels side by side, one is for viewing original and other is for previewing changes.
You can navigate through different image-related options present at the bottom of the window, such as; Metadata, Mask, and Image adjustments. For instance, an image in JPG format can be converted into GIF, just select the GIF and perform the actions from aforementioned image manipulation tools.
You can see the compression rate over the Optimized Image. It make changes to image in real-time allowing user to properly customize the compression, and flip/rotate the image. The In-place compare feature allows you to display the original image over the optimized image to observe small pixel changes.
Batch optimization can also be done with all the re-sampling options, click its respective button in toolbar, populate image list, and select a task to perform batch conversion.
It runs on all versions of Windows, testing was done on Windows 7 x86 system.
You can also check out previously covered image converters and optimizers; ImageConverter, Modi, and Image Tuner.