Re: GDK: fast image scaling - how?

[Tristan Van Berkom <vantr touchtunes com>]

        This is the most basic methid I know.
(You probably want GDK_INTERP_NEAREST
but GDK_INTERP_HYPER is working good
for me with downscaling).


Cheers,
                -Tristan

****** extract from gdk-pixbuf.h *********

/* Interpolation modes */
typedef enum {
        GDK_INTERP_NEAREST,
        GDK_INTERP_TILES,
        GDK_INTERP_BILINEAR,
        GDK_INTERP_HYPER
} GdkInterpType;


GdkPixbuf *gdk_pixbuf_scale_simple           (const GdkPixbuf *src,
                                              int              dest_width,
                                              int              dest_height,
                                              GdkInterpType    interp_type);

******* end extract *********

RevX gmx at wrote:
> Hi,
>
> I'm using gtk+ 1.2 and want to display some image data by using GDK. The
> image is already in memory but I want it to display at half size only (in each
> axis). Is there already a function that can do that ("scale down")? And if
> not, what would be the best (=fastest working) approach to it? (Btw, Gnome is
> not installed if there are any libraries for this).
>
> A second, related problem is, that I want to take a part of the original
> image and scale it up by a factor of 2 (like a magnifying glass). Now, is that
> the same problem as above or is it more simple to achieve?
>
> Btw, the up and down scaling hasn't to be of good quality (no anti-aliasing,
> etc.), simple pixel cutting/duplicating is fine. The image I have is an 8bit
> grayscale image (748x576).
>
> Thanks for helping in advance!
> Michael.
>
> --
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