Focus the point you click on the image
Bug 22694 imported from GNA! bug tracker
Submitted by: jehan on 2014-09-22 22:36:32
Additionally to the slider idea, which is a good idea and should also be done (bug #21111), I imagine another great way to focus.
I'd like to be able to click any point of the image when in preview mode, and have my camera to try and focus on this point.
Is this possible with libgphoto2? This would be awesome.
Comment by: danpb on 2014-09-23 18:52:13
For that idea to work, we'd need to be able to control which focus point the camera uses. In fact we'd need to know the positions of every focus point, and these are annoyingly different on every new camera. AFAIK, there's no way to get this position information, nor change the focus point with libgphoto.
Comment by: tobiasj on 2015-02-11 12:49:56
I thought about this problem and it could be possible if we:
- creating a focus stack
- calculating a depth of field
- looking at the color of the depth of field where the user clicked
- calculating the focus from this value
Things that may be problematic:
- I don't know how many images are needed for the focus stack to be useful.
- It may be slow to take the pictures and do the calculation.
- it is not usable for moving targets.
Some interesting links: http://www.stareat.it/sp.aspx?g=3ce7bc36fb334b8d85e6900b0bdf11c3#prettyPhoto http://bigwww.epfl.ch/demo/edf/ https://en.wikipedia.org/wiki/Depth_of_focus
Comment by: tobiasj on 2015-02-26 15:23:58
I just found this website, where someone has done this with JavaScript: http://dof.aws.af.cm/