Create several thumbnails from a single original image

[hiigara]

I want to create thumbnails of different sizes from the same source image. I am able to create a single thumbnail with this code:

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g_Magickwand = NewMagickWand();
MagickReadImage( g_Magickwand, "test.jpg" )
MagickResizeImage( g_Magickwand, "150", "100", LanczosFilter, 1.0 );
MagickWriteImage( g_Magickwand, "test_tn1.jpg" );
g_Magickwand = DestroyMagickWand( g_Magickwand );

Now I want to create another thumbnail from test.jpg:

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...
MagickResizeImage( some_wand, "300", "200", LanczosFilter, 1.0 );
MagickWriteImage( some_wand, "test_tn2.jpg" );
...

I could create another wand and call MagickReadImage again, but since this is for a busy internet server, there is probably a more efficient way of doing it, without reading the disk again. How can I keep "test.jpg" in memory while creating several thumbs?

[el_supremo]

If you want 300x200 and 150x100 you can create the 300x200 first, write it, and then just cut the image in half and write that.
If you want to (or have to) start from the original image each time, use CloneMagickWand to create a copy of the original wand.
e.g. do something like this pseudo-code:

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image_wand = readimage();
    clone_wand = CloneMagickWand(image_wand);
    do a resize of clone_wand
    write clone_wand
    destroymagickwand(clone_wand);

    clone_wand = CloneMagickWand(image_wand);
    do a different resize of clone_wand
    write clone_wand
    destroymagickwand(clone_wand);

etc.

Pete

[hiigara]

Thanks. CloneMagickWand is exactly what I was looking for.