Re: [gtk-list] Problems reading RGB values from GdkImage
- From: Martin Norbäck <d95mback dtek chalmers se>
- To: gtk-list redhat com
- Subject: Re: [gtk-list] Problems reading RGB values from GdkImage
- Date: Fri, 10 Dec 1999 19:55:56 +0100
Fri Dec 10 1999, AVILA BERMEJO, FRANCISCO JOSE ->
> In this example program I read a GIF image with 3 colors
> (in RGB values):
>
> * (0,0,0)
> * (255,255,255)
> * (198,198,198)
>
> I read this image the GdkMagic rutine ReadImage() and I convert it
> to a GdkImage with gdk_magick_to_gdkimage(). When I get the pixels of
> the GdkImage with the function gdk_image_get_pixel(), the initial
> RGB values are converted to:
>
> * (0,0,0)
> * (65535,65535,65535)
> * (50744,50744,50744)
>
> How can I get the original RGB values in the range of 0-255?. I need
> them to apply some filter to the images, like edge detection,
> sharpening, gaussian blur and others.
Divide them by 256? Shift right by 8?
But are they really returned like this? gdk_image_get_pixel returns a
guint32, which only has room for 4x8 bits.
n.
--
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