PHP imageconvolution

imageconvolusion always returns false

[killroy]

I'm working on a scrolling/zoomy sattelite map thingy and would like to apply a sharpen filter to non-integer zooms. I tried the new imageconvolution function but it doesn't seem to work.

This is the simple sample code:

<?
$myImage=imagecreatetruecolor(20,20);
$sharpenMatrix = array(-1,-1,-1,-1,16,-1,-1,-1,-1);
$divisor = 8;
$offset = 0;
var_dump(imageconvolution($myImage, $sharpenMatrix, $divisor, $offset));
?>

This simple prdouces:

bool(false)

does anybody know what I'm missing? Or is this function not functional yet? Has anybody a self-written verion handy that's not too slow?

Thanks,
SN

[jatar_k]

I did look around at this when you first posted it but didn't really find much.

did you get anywhere with it?

[ergophobe]

broken record here... I always find that image manipulation (as opposed to creation say) is easier and faster with ImageMagick. Have you looked into that?