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From: "Ahmad " <ahmad.humyn@gmail.com>
Newsgroups: comp.soft-sys.matlab
Subject: Presence of logical ones around a pixel in a certain direction and distance
Date: Mon, 12 May 2008 13:46:04 +0000 (UTC)
Organization: University of Lahore
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Hi there,

Lets say I have binary image. Given a pixel I want to find
the number of non-zero values around it in a certain radius,
in a certain direction. Lets say I have divided the region
around the pixel into 30deg regions (starting from north,
0-30 deg, 30-60deg ... 330-360 deg) upto a distance of x
pixels, so that it makes a radial region around the pixel
concerned, with spokes at every 30 degrees. I want to find
all logical 1 pixels in each region. What would be the
fastest way to perform this?

Eventually I want to do binning of the number of non-zero
values around a certain pixel. (According to my example
there will be 360/30 = 12 bins). Looking for an extremely
fast way...since I'll be doing this for many pixels


Regards,