gaussian blur does not preserve alpha

[rikkarlo]

Hi everyone, when I use the gaussian blur filter the edges of the picture become faded and transparent because it blurs the border without preserving the starting alpha, is there something that I'm missing or is it a new bug? in the tutorial it doesn't behave as it does in my version of affinity photo!
Thanks RF

[v_kyr]

Which APhoto version retail or beta and under which OS?

[Old Bruce]

What you are seeing is the nonexistent outside the image area being blurred and leaking their nonexistence into the image. Expand the canvas and just use a large sized Clone Brush to paint the outside and then blur, it will be better.

[RNKLN]

When you use the Live Gaussian Blur there's a Preserve Alpha checkbox (at least on Mac). See attachment. For some reason, it's not available with the destructive filter.