Unexpected extreme file size changes in the output file?

[Qayinz]

Hey, i am aware that there is a 99% chance that this is a misunderstanding on my end.
But when i used this on a 10mb PNG 4K render, along with the (incredible) removal in noise, the file size decreased from 10mb to 7mb.

I can only assume this isn't a lossless reduction. Can the reduction/encoding be disabled? or is this by design and is a part of the denoising process?

[mojo-jojo-7]

There's a couple of reasons why this can happen

• Denoising an image inherently decreases the "complexity" of an image, hence fewer bytes are required to store the image data
• Your original PNG file could have been encoded inefficiently

It's usually the first case. Don't worry, PNG always uses lossless compression. So, apart from the intended change in image quality from noise reduction, there is no other downgrade happening here.