IMAGECT

Name

imagect

Purpose (one Line Only)

Convert a byte image to a rgb image using a standard color table

Description

This tool lets you re-create the illusion of using decomposed color
that was our only option many years ago. 24-bit color is generally
a lot more useful but false color image display is still handy. The
result of this function is to return a 3-plane rgb color image where
the input byte image has been converted to rgb according to intensity
into the chosen color table.

Calling Sequence

result=imagect(image,table)

Inputs

image - Byte scaled image to convert
table - IDL standard color table number
-or-
A string which is the name of a local color table in your
path. These files are compatible with cpalette.pro. The files
are named color.<table>.dat. If you give the table name it will
be loaded. However, not all of these local color tables have
256 colors. Those that are not are expanded by replication to
this length meaning some indexes will be duplicated.

Optional Input Parameters

Keyword Input Parameters

BLACK - Flag, if set will replace the first color in the lookup table
with black so that 0 in the image comes out as black on the
display. The lookup table itself is not modified, only
the resulting output.

Outputs

return value is a [nx,ny,3] byte cube where nx,ny is the size of the
input image.

Keyword Output Parameters

Common Blocks

Makes use of mwb_palette_com managed by cpalette.pro

Side Effects

If you use a local palette, the loaded (and thus default) palette may
change.

Restrictions

Procedure

Here's an example. Given "image" is a byte-scaled image (use bytscl
ahead of time if you need to):
tv,imagect(image,34,/black),true=3
This creates a false-color image where intensity has been mapped to color
using the Rainbow2 standard IDL color table. (see loadct documentation
for a list of color tables).

Modification History

2015/11/08, Written by Marc W. Buie, Southwest Research Institute
2016/01/12, MWB, added option of local color tables.