You can isolate just about any detail in an image in AE but it requires a fairly high level of skill and pre-production planning. The better the pre-production planning and the higher the quality of the original footage the easier it is to do. It's all about creating mattes (masks). There is no magic click the button solution to the problem.
Depending on the footage it may require you to:
- Track in Mocha, Stabilize Motion, Track Motion, Camera Track, Mask Track
- Rotoscope, Rotobrush
- Adjust color channels
- Use blend modes and pre-comps and hand roto to combine multiple mattes into one usable matte
- Track matte and adjustment layer with the color (maybe tint) effect applied)
To learn about those techniques type any of the items in the Search Help field at the top right corner of AE and check out the community resources.
The basic procedure is to isolate the hair from the rest of the image. This is usually a 2 step process involving a rough selection (rotoscope, track in Mocha) on a duplicated copy of your footage layer then isolating and separating the hair from the immediate background by manipulating color or luminance channels so you can create a matte to limit a color change effect. This is why pre-production planning and high quality cinematography is essential to the process. Blond hair blowing in the wind with your model walking through a field of wheat is going to be very tough. Blond hair blowing in the wind with your model against a dark background that is pretty featureless is just going to be difficult.
Open up the footage you are planning to use and take a screenshot and drag it to the reply field on this forum so we can see what kind of footage you are dealing with. These still frames are all from video clips available on Adobe Stock. If you have not shot the footage yet find something similar and point us to it.
Really difficult because of the soft edges and soft foreground - maybe 4 hours work for a 10 second shot:
Easier - maybe a couple of hours for 10 seconds:
Well planned and shot - maybe 45 minutes for a 10 second shot:
The hardest part of this shot is separating the hair from the face.
Last but not least - Good luck with this one:
It would be possible but motion blur and the uneven background would be a bear to deal with.
Here's a start on the "easier" shot - the workflow is:
- Duplicate the footage
- Mask Track the outside of the hair and the face
- Start working on the edge detail of the hair using Colorama to get some dark edges on the outside of the hair
That's as far as I got this morning. Took me about 15 minutes. Here's what it looks like:
The procedure will be repeated for other color values using additional masking until you have enough layers to combine so you can get a decent black and white mask generated where the hair is black and everything else is white. I'm guessing about 4 or 5 more duplicates. The girl is walking so I would probably motion stabilize the entire thing so the hand roto would be easier. I would just use a black solid to fill any holes in the between the edges. All of the grayscale duplicates would be pre-composed and that would be used as a track matte for an adjustment layer that I would use to tint the hair. The entire 15 second shot would probably take me two to three hours to perfect. Here is what it looks like with one quickly drawn black shape layer to fill in the hair. The hard edges around the face and shirt can be fixed with more pre-mattes. The blond is now a red head:
What a great idea for a tutorial. I should write a book -- hint hint