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Re: Color table question [message #427]

Fri, 14 August 1992 14:38

snoopy
Messages: 6
Registered: March 1992

Junior Member

If, after trying all the previous suggestions, the image still
doesn't improve the problem may lie in the distribution of the
data across the dynamic range of the display system. This can
be improved by normalizing the data-set so that the frequency
distribution (histogram) or the pdf (probability density
function) of the data will be flat across the entire range of
the data or the display system.

You can do a histogram equalization (or normalization) on the
data with the following command:

newdata = HIST_EQUAL(olddata)

and then redisplay the modified data.

Although this will improve the dynamic range of the data itself,
the result still depends somewhat upon the choice of the color-
table.

--rv

P.S.

Also, in the original posting where the data was scaled to fit
into bytes (using BYTSCL) and values less than 10 were zeroed
out, the following version of BYTSCL using keywords min and max
may be used instead with perhaps better results:

newdata = BYTSCL(olddata, min=10, max=max(olddata))

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[Message index]

		Re: Color table question By: snoopy on Fri, 14 August 1992 14:38
		Re: Color table question By: hofer on Tue, 11 August 1992 03:13

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