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Re: invert_ct? [message #4579 is a reply to message #4578]

Wed, 07 June 1995 00:00

sjt
Messages: 72
Registered: November 1993

Member

dean@phobos.cira.colostate.edu wrote:

: There is h_eq_ct and gamma_ct, but is there a invert_ct to invert the
: color table of a raster image. If not, what would be the simplist way
: to invert the color table of an image with IDL?

: Bonus question - what would be the simplist way of inverting the values
: of an image itself?

: Kelly Dean
: CSU/CIRA

Unless I seriously misunderstand what you are trying to do, it seems trivial:

tvlct,r,g,b,/get
tvlct, not r, not g, not b

Similarly for a byte image, (not image) will do a bitwise inversion. For
other types the action is the same but results are not quite as obvious
because other types are signed.

--
+------------------------+---------------------------------- --+---------+
| James Tappin, | School of Physics & Space Research | O__ |
| sjt@star.sr.bham.ac.uk | University of Birmingham | -- \/` |
| Ph: 0121-414-6462. Fax: 0121-414-3722 | |
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[Message index]

		invert_ct? By: dean on Wed, 07 June 1995 00:00
		Re: invert_ct? By: sjt on Wed, 07 June 1995 00:00
		Re: invert_ct? By: knipp on Wed, 07 June 1995 00:00

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