Generally large images can take a long time to download even on a broadband connection and if a post becomes very popular on the web, optimising images for size can mean the difference between a web server being able to cope or not.

The best method is to optimize the image before sending them. Radical Image Optimization Tool (RIOT) is a freeware tool for Windows which is an image optimizer that will let you to visually adjust compression parameters while keeping minimum file size.  You can select image format from JPEG, GIF or PNG for your output file.

Also see: Compress and Optimize Images Online using Smush.it

The app uses a side by side (dual view) or single view interface to compare the original with the optimized image in real time and instantly see the resulting file size. You can control compression, number of colors, metadata settings and much more.

Key Features of  Radical Image Optimization Tool (RIOT):

• Open many image types including rare/scientific types
• 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).
• 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);
• Batch support (process multiple files at once)
• 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
• Basic image adjustments: brightness, contrast, gamma, invert
• Visually reduce number of unique colors for PNG and GIF images in order to reduce filesize
  (two quantization methods are available: Xiaolin Wu and NeuQuant neural net)
• Resize image by using well known resample filters (ex: Lanczos3, Catmull Rom, Bicubic, and others)
• Out-of-the-box support for external PNG optimizers (optipng, pngout, etc)
• The compression and the results are comparable to those of commercial products, even higher.
• Adaptive logarithmic tone mapping algorithm (Drago) used for HDR images

RIOT can be used as plugin for programs like The GIMP, IrfanView or XnView. The app is lightweight, fast and simple to use, yet powerful for advanced users

Download RIOT - Radical Image Optimization Tool for Free.