#Jpeg file size reducer windows#
Two document windows open in Photoshop, each displaying a copy of the same photo.īut are they really the same image? Appearances can be deceiving, especially on a computer screen. Here, I have two document windows open in Photoshop, each one containing what appears to be the same image: It does help, though, for us to see and understand what's happening to our images, especially for those of us who, up until now, have been convinced there's no difference in image quality between a compressed and uncompressed digital photo. In a perfect world, sure, but that's just not realistic. Now, this isn't to say that we all need to stop compressing our photos. The Difference blend mode isn't used very often outside of the special effects world, but it does a great job of showing us how much garbage (yes, I said garbage) we're adding to our jpeg images when we compress them. Any areas in both layers that are exactly the same appear as pure black, while areas that are different in some way appear as strange colors. The Difference blend mode gets its name from the fact that it looks for differences between two layers. To see exactly what's happening to our images, we'll use Photoshop's Difference layer blend mode. But thanks to Photoshop and one of its rarely-used blending modes, the horrors of jpeg compression become strikingly clear.ĭownload this tutorial as a print-ready PDF! Unfortunately, it also reduces image quality, although it's not always easy to see what sort of negative impact the compression is having on the image, especially when viewing it on a computer monitor. Since the jpeg file format is still the format of choice for digital photos, even though it's been around for more than 15 years, compressing images usually means using jpeg compression, which does a great job of reducing the file size. Sometimes, we need to compress them to make our file sizes smaller, especially if we're emailing them to a client or to family members, or posting them on a website. It's a fact of life when it comes to working with digital photos and images.