Wavy artifacts when saving render as PNG?


(Dumpskin) #1

Whenever I save my rendered image as a PNG, I get what look like compression waves in my picture.

When I import the image into photoshop, and change the channel bits from 16 to 8, or from 8 to 16 then back to 8, the waves disappear into how I want the image to look.

Is there a way to prevent this from happening without having to import it into photoshop? I save the images as either 8 or 16 bits per channel, and in RGB mode with 100% compression, which blender says is lossless.


(Emir Sinan Gürlek) #2

this doesn’t sound good. try %10 compression (if not typo).


(Dumpskin) #3

I’ll try that. 10% is blenders default iirc, but I assumed the compression amount doesn’t matter since blender says it’s lossless. So when I render I would always put it to 100% since I would want it to be as small a file as possible. Does ‘lossless’ not mean what I think it means?


(cdog) #4

Have you tried increasing dithering? It’s under Post Processing panel and should help with banding artifacts.


(Emir Sinan Gürlek) #5

Where do you see that information?


(Dumpskin) #6

When you hover over the compression slider, the tooltip says 100% is the maximum lossless compression.


(English is not my native language) #7

It is lossless compression. Do what @cdog recommended:
https://docs.blender.org/manual/en/dev/render/post_process/panel.html