Is there a effect to do a diagonal blur?

[Lpainter]

I was reading that diagonal blurs can help with compression in png's.

 

http://pngmini.com/lossypng.html

 

Does Paint.net have a averaging filter on the diagonal?

[Ego Eram Reputo]

I don't recall such a filter. Rather than messing with the image in this way, try using either the PNG preprocessor or OptiPNG plugin.

The preprocessor simplifies an image in order to enhance the compression which PNG uses. Use it prior to saving. It's supposed to be almost undetectable visually.

OptiPNG forces the filesize down by compression while saving is being done.

If you really want to squash the filesize - try both.

[david.atwell]

I second OptiPNG. Using just OptiPNG by itself, I can usually get a smaller filesize than a JPEG on high (80-90) quality. It's a very solid algorithm.