CHAPTER 11 HOW THE DIGITAL DARKROOM MAKES GOOD PHOTOS INTO GREAT FANTASIES^175
The software also makes a record of
what is inside each of the regions the
dots define. It uses this information when
it performs a cross dissolve, replacing
pixels in one photograph with pixels from
the other. The software simultaneously
repositions the transported pixels and the
polygons they form to warp the emerging
image so the pixels move steadily toward
the positions they occupied in the picture
from which they came.4
The end result is the same as the cross dissolve: One picture replaces the other. But when all the stages are displayed in an
animation, warping makes the subject of one photo morph gradually into the other. (By working with two copies of the same
photo, you can warp without dissolving. The effect is to distort the original image so it grows a bigger nose, longer hair, or
bulging eyes.)5