Gaussian blur is removing all transparent pixels from image

I am trying to make a transparent image with a black shape on it.

Then use IMG_FILTER_GAUSSIAN_BLUR on it to blur the shape a little.

Problem is as soon as I apply blur filter, entire image loses its transparent pixels, and entire image becomes black.


So when I copy the final image on a white image, then instead of getting a transparent image with some blurred black shape, I get a completely black image...

What is wrong with this?


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$image= imagecreatetruecolor( 200, 200 );...

Gaussian blur is removing all transparent pixels from image

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