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Re: Chained "compare", then removal.

Posted: 2013-09-03T22:00:54-07:00
by agamemnus
fmw42 wrote:see -evaluate-sequence with And, Or, Xor whatever you need. http://www.imagemagick.org/script/comma ... e-sequence. Use

convert -list evaluate

to get the full list of options.
Thanks. Interesting. Edit: I tried all of them, and none of them give me common pixels...

Slightly off-topic, but I noticed this bit in the documentation:
Averaging hundreds of images of the same fixed scene, can be used to remove most transient effects, such moving people, making them less important. However areas that get lots of transient effects may have a 'ghostly blur' left behind that may be very hard to remove.

As video sequences are notoriously noisy when you look at the individual frames, you can average a number of consecutive, but unchanging, frames together to produce much better cleaner and sharper result.

Matt Leigh, of the University of Arizona, reports that he has used this technique to improve the resolution of microscope images. He takes multiple images of the same 'target' then averages them all together to increase the signal/noise ratio of the results. He suggests others may also find it useful for this purpose.
If you have let's say 100 high-quality still images of an area with moving people, you could remove the blur completely by weighing occurrence of each pixel (or pixel component) in a root-mean-squared kind of way. For instance, 5 instances of a greyish type of pixel could be weighed at 25, while 2 instances of a bluish pixel could be weighed at 4.