Welcome


	There was no demo in class, but you’ll be seeing and using this program soon!


	OK, so we all know that images can now be faked.
	But unless you’ve taken a CS graphics course or are technically inclined, your knowledge of photo-editing is probably limited to and represented by the photoediting tools in Adobe Photoshop.

	But “brush”, “clone” “erase” and “smear” are not inherent features of computer graphics.
	They are defined by programmers at Adobe
	(inspired by work done by Bill Atkinson, creator of Mac Paint, and others) and loosely based on traditional painting and photo work.

	Let’s look behind the metaphors and “under the hood” for a moment at what’s really going on in a photo editing program.

	GTT example-live demo

	Goal: correct mental model: Photoshop isn’t about “painting” or “darkroom work” (there used to be a program called digital darkroom. It’s about reassigning pixel values…)
	Sometimes a UI metaphor helps people understand what is possible—but not always.