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Re: Alpha blending with object graphics - different color palettes do not work [message #75780]

Wed, 04 May 2011 09:43

djh
Messages: 1
Registered: May 2011

Junior Member

On May 4, 4:11 am, LNpellen <lnpel...@gmail.com> wrote:

> This is how I create the alphaDose:
> alphaDose = BYTARR(2, size[0], size[1], /NOZERO)
> alphaDose[0,*,*]=dose
> alphaDose[1,*,*]=255*alpha ; where alpha is a factor between 0 and 1

I ran into this last year.

Try converting alphaDose into a [4,n,m] array to use in the overlay
image:

alphaDose = Reform( alphaDose, [1, size[0], size[1] ], /overwrite )
oPaletteDose->GetProperty, red_values = r, green_values = g,
blue_values = b
alphaDose4 = [ r[alphaDose], g[alphaDose], b[alphaDose], alphaDose ]
alphaDose4[3,*,*] = 255*alpha

The background image can still use the palette.

Don

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[Message index]

		Re: Alpha blending with object graphics - different color palettes do not work By: djh on Wed, 04 May 2011 09:43
		Re: Alpha blending with object graphics - different color palettes do not work By: David Fanning on Wed, 04 May 2011 09:33
		Re: Alpha blending with object graphics - different color palettes do not work By: Karl[1] on Wed, 04 May 2011 09:17
		Re: Alpha blending with object graphics - different color palettes do not work By: David Fanning on Wed, 04 May 2011 05:30
		Re: Alpha blending with object graphics - different color palettes do not work By: LNpellen on Wed, 04 May 2011 22:50

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