rmalayter

Dammit, now that I am in the office I cannot reproduce. I did use a screenshot-to-PNG for the images, but made sure that zoom was set to 100% in paint.net first. Maybe I have some weird monitor scaling going on with my laptop when it is undocked. Have to mess with the icky HP display driver to make sure that isn't the case. I have seen scatterplots from "synthetic" data generated by poor RNGs that clearly show diagonal or rectangular regularites, and that's what I guessed was happening here. But I am flummoxed as to why I cannot reproduce today, as was able to do so repeatedly yesterday wh

The "squares" pattern is quite visible at 100% pixel-for-pixel zoom, even outside of paint.NET in a browser, using this second test image I posted previously above: http://forums.getpaint.net/uploads/monthly_01_2014/post-134862-0-38051500-1389670699.png So it is not a problem with any resizing algorithm in Paint.NET or elsewhere. To reproduce in Paint.NET v3.5.11, start with an 800x600 canvas, fill with black, then go to Effects->Noise->Add Noise. Choose intensity = 64, saturation = 100, coverage = 100. I haven't tried on another machine yet, but it certainly looks like you

Sorry, I had to crop and it wasn't as clear after that. See teh following two attachments, one showing the add noise command, and then the same image after contrast adjustment showing the "pattern" more clearly. The size of the "squares" appears to be about 75 pixels on a side with this example.

While usinng the Effects->Noise->Add Noise function, I was surprised to see a clear pattern of "squares" emerge from the noise. This is clearly the result of using a "bad" pseudo-random number generator (PRNG), such as System.Random, which is a simple linear generator. While I haven't looked at the source yet, I assume System.Random is being used. A switch to a better PRNG would prevent any strange effects, and probably improve the appearance and performance of all filters and functions which utilize random numbers. Switching to a cryptographic RNG such asSecurity.Cryptography.Random