[IMAGE-SIG] histogram

Andrew Kuchling amk@magnet.com
Sat, 4 Oct 1997 20:38:53 -0400 (EDT)

jiang@geosun.indstate.edu (Yu Jiang) wrote:
>I created a big image by merging a number of small images together
>using PIL. However, the big image looks like a chess board because the
>histograms of the each small images are different.  I want to smooth
>the chess board like stuff by uniting the histogram of the big image.
>I wonder anybody can give me any hint of doing so?

	You might want to ask about this on sci.image.processing,
because it may be fairly complicated.  You'd have to determine some
universal histogram, and recolour all the small images to match that
histogram.  But I have no idea how you'd get the universal histogram;
presumably one would want to have it be as similar as possible to all
the histograms on the subimages, in some sense.

	Even after that, there would probably be visible joins between
the subimages because they have different values at the edges.  You
could run an averaging filter over the joins and try to smooth that
out, at the cost of some blurring.

	Andrew Kuchling

IMAGE-SIG - SIG on Image Processing with Python

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