Author Topic: Sharpening/Blurring Values in Frame Buffer  (Read 1705 times)

2021-01-12, 17:50:38

Kum

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Hello everyone!

I would like to learn a bit more about sharpening/blurring values and I have some questions. I have searched through the forum and also online but couldn't fine a solid answer (or nothing at all). Only reference to this topic was Dubcat's post from 2017. I'll attach it below.

So my questions are:
1. Are sharpening and blurring values resolution dependant?
2. If the answer to 1 yes, what is the correlation between numbers (i.e. if I multiply the resolution by 2, does that mean I need to multiply the radius by 2, too)

To me, radius means it's working somehow related to pixels. Like in photoshop, higher the resolution, bigger the resolution. But I don't know if Corona Renderer automatically calculates input values depending on the resolution for us. Meaning I get the same sharpness throughout different output resolution with the same radius value.

In short, I am trying to figure out how to scale these radius values between 1K, 2K, 4K and so on.

Obviously end result of 1K and 4K are different by nature, 4K being sharper by default. But I'm trying to understand just how this thing works.

Looking forward to your replies.

Thank you!




These radius settings are at 1k, multiply K by whatever you are using.

2021-01-13, 11:37:44
Reply #1

maru

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The "resolution dependent" and "resolution independent" terms may be easily misunderstood, so:

The "sharpen radius" and "blur radius" are simply specified in pixels. So if you render two images showing a single pixel of one color against some other color in 1000x1000px and 4000x4000px and you apply the same values of "sharpen radius" and "blur radius" (for example 2) to both of those images, then the effect on that single pixel will be identical in both cases.

2021-01-13, 13:54:51
Reply #2

Kum

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Thank you very much for your fast reply. It seems clear now. I will make a few more tests to better visualize this.

2021-01-13, 14:00:36
Reply #3

maru

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Another way to put it is: it works the same as applying blur or sharpen filter in Photoshop. :)