Here are some key features of "Portable RIOT":

· Open multiple graphic file formats by looking first at the magic number (it does not need file extension to recognize format)including support for uncommon images types (up to 128 BPP, integer and floating point. EX: hdr images, 16 bit grayscale, etc). Adaptive logarithmic tone mapping algorithm (Drago) used for HDR images
· Save and optimize JPEG, GIF and PNG with a simple, clean user interface
· Works in dual view: (original - optimized image) or single view (optimized image). Automatic preview of resulting image
· In-place compare function (alternativelly display the original image over the optimized image to notice small pixel changes)
· Compress files to desired filesize threshold
· Fast processing (all is done in memory); see instant results including resulting filesize
· Decide if you want to keep metadata (comments, IPTC, Adobe XMP, EXIF profiles, ICC profiles). Unsupported metadata is removed
· Transfer metadata between image formats (destination format must support them)
· Common tools: pan and zoom, rotate, flip
· Resize image by using well known resample filters (ex: Lanczos3, Catmull Rom, Bicubic, and others)
· The compression and the results are comparable to those of commercial products.