Content-type: text/html Manpage of imheq

imheq

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NAME

imheq - Apply histogram equalization to an image  

PERSON RESPONSIBLE

nebk  

CATEGORIES

map manipulation  

DESCRIPTION

IMHEQ -- applies histogram equalization to an image. This technique generates a cumulative histogram of an image. The ordinate for this histogram (number of pixels) is then also discretized into the prescribed number of bins. Each image pixel is then replaced by the value of the cumulative histogram bin that it contributed to. This essentially means that in terms of a non-cumulative histogram of the image, equal numbers of pixels have fallen into each intensity bin so that the bins are not of equal intensity width. This technique enables you to see best the intensity range that has the most pixels.

Image pixels which are flagged by the image mask will not contribute to the histograms. However, they will be equalized in the output image (although their mask will be unchanged).

 

PARAMETERS

in
The input image. No default.
out
The output image. No default.
nbins
The number of bins for the image histogram. Default is 128.
range
The intensity minimum and maximum to bin in the histogram. Pixels outside this range are set to the nearest limit. Default is to use the full image plane range. Over-rides OPTIONS=GLOBAL below.
options
"global" means use the global image minimum and maximum as the
   histogram limits for all image planes.  By default, each
   image plane is equalized with the intensity minimum and 
   maximum from that plane.
device
PGPLOT device to show plots of the histograms & discretized cumulative histogram. Will plot after each plane, so really of use only for single plane images


 

Index

NAME
PERSON RESPONSIBLE
CATEGORIES
DESCRIPTION
PARAMETERS

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Time: 18:35:38 GMT, July 05, 2011