Google have released this encoder for JPEGs which promises 20-30% smaller file sizes without any perceptible loss of quality.
The history of the GIF—a tale of licensing, compression, and standards.
Some good thinking from Jason here. In a roundabout way, he’s saying that when it comes to responsive images—as with just about every other aspect of web development—the answer is …it depends.
You’ve probably seen this already, but it’s really worth bearing in mind: when you’re scaling up JPGs for retina display you can safely reduce the image quality by quite a lot—to the point of getting the exact same file size as a higher quality image that’s half the size.
This looks like a really handy tool for reducing the file size of JPEGs without any perceptible loss of quality (in much the same way that ImageOptim works for PNGs)—available as a Mac app or an installable web service.
An in-depth analysis (graphs! data!) of how popular sites are using—or not using—compression.