colorifying with GIMP and other PP stuff

I've been doing quite a bit of PP work lately, and today was no exception. Apart from that this was for work...

We have some clipart. We wanted the guy to have a different coloured shirt.

Right. After several completely false starts, I worked out the (a) way to do it.
- use the magic wand to select correctly, based on Saturation (not composite!) - though the white also worked well with all of the others.
- copy-paste the reserved section to another pic
- the stuff you want to colour: edge-detect
- convert to grayscale
- invert
- set the levels so you have mainly black / white / grey
- remove any imperfections (do it properly or it will show!)
- re-set the levels. I needed to return this lot to grey, because of the application (this is easy - move the bottom-left anchor point of the curve up the left axis - sorted)
- if you need to clean up again, do so
- now use colorify
- don't forget that colorify works as a glass filter, therefore it's over the top of what was there before. Since this is company stuff, the colours need to be right, so I was pasting the shirt as a new layer into the pic with the face - and then removing again after saving.

Don't forget that PNGs have transparency available, but if you're saving from a website, the transparency may not exist, leaving you with nice backgrounds you can't necessarily explain.

There's doubtless another way to deal with this stuff with another layer, and I'll probably try that next time I have to do something like this, but for the moment I'm reasonably happy.

The Color mixer did some interesting stuff, but it never really hit what I wanted. In an Ideal world, I'd probably actually convert the inside of the shirt to transparent to have consistent shirt outline colours, never mind what the internal one is. Since it's "only" for some PPTs, I'm not going to worry too much about that right now. It looks OK and I don't think we'll be using this stuff much.

I'm surprised, but the trick with edge-detect and grayscale and inversion was way more effective than I expected, so I'm happy.

Another thing I got hammered home over the weekend: use smudge with minimal opacity (say 10%) for minimal corrections. Another layer, of course, would do the same thing and allow you to change the opacity of the complete layer, but localized also works for certain things. cloning and using local colours is absolutely essential to cover up small imperfections (teeth spinach), as is working at pixel level. Even a single pixel shows up really well if it's the wrong colour.

- Bret