JPEG uses a “lossy” compression algorithm. That’s basically the secret of why a JPEG version of an image can be so much smaller than a PNG or TIFF; it’s because the JPEG throws away some of the information. Continue reading Resaving JPEGs
This is a very simple subject — complicated by people like me arguing about proper use of terminology, and people trying to explain differences that other people haven’t even noticed, and people pontificating on things they don’t adequately understand.
Printing? Who cares about that any more? Don’t we all just look at our photos on the screen?
It used to be the only way to get color. It’s still the way most color is reproduced (offset printing, mostly). It’s what really goes on inside chromagenic papers. And it’s well supported in PhotoShop and other modern image manipulation programs.
But it’s still weird. Continue reading Composite Color
This is a bit of a pet peeve of mine. I’ve seen many people get terribly confused by the way scanning programs, and some image manipulation programs, associate a DPI with bitmap images. I find it particularly confusing in scanner interfaces, myself. Continue reading DPI Means Nothing On the Web