I’m a big fan of Irfanview. It’s one of the best examples of how I think all software should be: small, light and with just the right features. I use it every day, and can’t recommend it enough. But Irfanview isn’t perfect. It applies the default worst icon I’ve ever seen to your images, but more importantly it’s not very good at optimizing images for the web. JPEGs saved from Irfanview were consistently worse in both quality and file size compared to the same saved through Photoshop’s ‘save for web’ feature. That’s where RIOT comes in.
The ‘Radical Image Optimization Tool’ can either be used as a standalone program or as a plugin to Irfanview. It takes your image and lets you set things like image format (jpg/gif/png), color depth and compression levels. It also allows you to scale, rotate and flip the image before saving and optimize to a specific file size. The only thing I really miss compared to ‘save for web’ is dithering with indexed color images, but I have to admit I rarely use that anyway. On the other hand, RIOT has a few settings that Photoshop doesn’t have, such as control over chroma subsampling.
With RIOT, saving images for use in blog posts has gotten a lot easier and quicker for me compared to going through Photoshop. It works really well and is free to boot.