Tip - Removing 'ghosts'

[Mike Shaw]

Sometimes when morphing objects (say) or people even, against a masked or alpha channelled background, ghost images of the second, target picture can appear in the alpha area, towards the end of the morph.

This is unsightly of course, and can spoil the effect.

As a solution which works 90% of the time, draw a multiple-dot line outside of the object around and fairly close to the edge of the main image in the area where the ghost image appears. On the second image, again position the line outside and close to the equivalent area of the main image - with a new shape, if necessary.

More often than not, it prevents or inhibits the ghosting effect.

[Mike Shaw]

Yep. I wrote that (a few years ago!), and it confused me too reading it back now. And I know what it was supposed to mean!

Basically, sometimes you get horrible unwanted 'shadows' and unsightly shapes shooting out from something that is being morphed. Something to do with the way 'triangulation' works, I believe. Anyway, if and when you get such nasties, draw a connected line round the object/person that is showing the trouble, and that can help to 'restrain it. Of course the 'barrier' line has to be drawn on both the 'before' and 'after' photos.

Is that a wee bit clearer? probably not. I'll go back into hibernation ...

[grantland]

Tip by Mike Shaw on removing ghosts is an excellent. Would just add that at least for line art drawings, need to make sure no point touches the edge of the frame - that's where my worst ghosts appeared. Once I added a couple of pixels and used Mike's formula, it worked like a chart. Well done, Mike!...Grant