| Re: writing gray scale GIFs from a 24bit machine [message #18781] |
Mon, 07 February 2000 00:00  |
reardonb
Messages: 16
Registered: December 1999
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Junior Member |
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Liam,
I installed your saveimage.pro program and it is working great. Thanks!
Unfortunately, I do not fully understand what I was doing wrong. Could
you enlighten me? Thanks.
-Brian
In article <87fnvl$ev$1@nnrp1.deja.com>,
reardonb@my-deja.com wrote:
> Hi,
> I'm having trouble creating gray scale GIF images that accurately
> reflect what is on my screen. I'm using a Mac and this problem does not
> exist when the colors are set to 256 but if the colors are set to
> thousands or millions I get a saved GIF image that has one color band
> that should be almost black but is instead almost white. I get this
> problem for gray scale color pallets such as loadct, 0. If I set the
> color pallet to loadct, 39 the saved GIF is very much like the screen
> image. The code I am using is the one David Fanning suggested and is
> attached below. I would like for this code to work on any system with
> any color pallet and any monitor color setting. Any help would be
> appreciated.
> Thanks.
> -Brian
>
> device, decomposed=0
> loadct, 0, ncolors=20, bottom=0
> wset, info.wid
> device, Get_visual_depth=thisdepth
> if thisdepth gt 8 then begin
> image24=TVRD(True = 1)
> snapshot=color_quan(image24,1,r,g,b)
> endif else begin
> snapshot = tvrd()
> tvlct, r, g, b, info.bottom, /get
> endelse
> write_gif,filename+'.gif',snapshot, r, g, b
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
>
Sent via Deja.com http://www.deja.com/
Before you buy.
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