[ptx] Enblend suggestion: focus score weighting

[Sebastian Nowozin]

Hello Andrew and ptx people,


lately I have been stitching a very large panorama with a complicated setup (a
glass-shelled visitor platform on a skyscraper with a ~30m radius circle to
walk to get all the pictures). Anyway, the net result was that I had 109
pictures, some of which were clearly out of focus and most were redundant and
overlapping. I was faced the problem of how to easily find the out of focus
pictures while still retaining the whole panorama.

  At first I thought maybe enblend could help and calculate some "focus score"
value for each image or even just parts of it, and use it to prioritize the
order of images, leading to an optimal end result, using the minimum
out-of-focus part of the images possible. And also, as far as I understand for
enblend an image is either completely redundant (removed), or used completely.

  The more I thought about this problem, the more attractive a generic solution
appears to me: For all redundant overlapping images, prioritize the images
based on a in-focus weighting function and use only those part of the image
that scores highest among all images covering that part (except the image it
will be blended with of course, or use a "minimum border size" threshhold).

  While my problem is easily fixed by more careful photographing and manual
sorting of the images, there is a interesting possibility if such feature would
be possible: You could take an image that is in-focus everywhere. Imagine
taking 8 images from the same POV but changing the focus everytime. Now it
would be easy to stitch and merge them all into one all-in-focus image.

A quick search brought up the following paper:
http://citeseer.ist.psu.edu/549905.html
The part about "focus score" is interesting.

  Is such feature possible or can this already be done with existing tools?


Thanks for consideration,
Sebastian

-- 
nowozin at cs.tu-berlin.de --- http://user.cs.tu-berlin.de/~nowozin/