LS

Name

Purpose

Scale image between percentiles 1 and 99 (or specified percentiles).

Calling Sequence

out = ls(in, [l, u, alo, ahi])

Inputs

in = input image. in
l = lower percentile to ignore (def = 1). in
u = upper percentile to ignore (def = 1). in

Keyword Parameters

Keywords

SCALE_ON=arr Array to determine scaling on. If not
given then input image in is used. As a special case
may give a 2 element array: [lo,hi] to scale to 0, 255.
TOP=t Max byte value for scaling (def=!d.table_size-1).
/QUIET Inhibit scaling message.
NBINS=nb Number of histogram bins to use (def=2000).
/NOSCALE Do not actually scale the data (returns 0).

Outputs

alo = value scaled to 0. out
ahi = value scaled to 255. out
out = scaled image. out

Common Blocks

Notes

Notes: Uses cumulative histogram.

Modification History

R. Sterner. 7 Oct, 1987.
RES 5 Aug, 1988 --- added lower and upper limits.
R. Sterner, 1995 Dec 15 --- Added SCALE_ON keyword.
R. Sterner, 1998 Jan 15 --- Dropped use of !d.n_colors.
R. Sterner, 1999 Sep 15 --- Added /NOSCALE.
R. Sterner, 2002 May 22 --- SCALE_ON may be [min,max].
R. Sterner, 2003 Feb 04 --- Listed value for constant image.
R. Sterner, 2003 Jun 27 --- More histogram bins.
R. Sterner, 2003 Jul 08 --- NBINS keyword.
Johns Hopkins University Applied Physics Laboratory.
R. Sterner, 2010 Jun 04 --- Converted arrays from () to [].
Copyright (C) 1987, Johns Hopkins University/Applied Physics Laboratory
This software may be used, copied, or redistributed as long as it is not
sold and this copyright notice is reproduced on each copy made. This
routine is provided as is without any express or implied warranties
whatsoever. Other limitations apply as described in the file disclaimer.txt.

LS