XnView Software

Hi,i've used XnView for sometime now & it's a program i couldn't do without,though i'm not knowledgeable enough to use it to its full potential.
My question is,from Filter>Effects,i can easily create a great drop shadow & apply it to an image as attached, but there's a huge white border around it.I just want the image & shadow,so it looks good on a black or dark desktop wallpaper etc.
Is there anyway of creating the shadow without the white background?Or second best,removing the white afterwards?
Thanks for your time.

XnView adds a bit too much border for the shadow. I don't see a setting to reduce that.

Currently, there's only the second best solution (workaround):
Use "Image > Automatic Crop", pick the background colour using the colour picker, and then apply cropping.

Thankyou,i'll try that.