Remove grain from posterised black and white image

[Samweow]

So I posterised this image, I then converted it to black and white. I would like to get rid of most of the grain on the face, so that the face is mono color but you can still see the eyes, nose and mouth. some grain would be all right but I want way less. I fiddled around with the denoise tool, but nothing seemed to make a difference, even after merging the layers.

 

I think the core of the problem comes from not being able to posterise my image enough. I brought my posterise down to the lowest level(2), but you can still see blue, red, yellow, green, turquoise and black in this image. That's too many colours.

 

Original image

[stokerg]

Hi Samweow,

You could try Denoising the original image, then using the Posterize adjustment, then the Black and White.  As the leftover pixels on the face aren't technically noise, the denoise filter won't remove them.  But you could paint over them with a brush or use the Clone Tool to clone over them from a clear part of the face.

I'm sure if anyone else has a better method, they will reply  

[Palatino]

I went a different way.

 

Edvard_Munch,_1893.afphoto

[Samweow]

@stokerg

Is there a way to do some kind of thresholding within Affinity like described in these screenshots?

[firstdefence]

What exactly are you aiming for?

[Samweow]

On 7/24/2020 at 12:22 PM, firstdefence said:

What exactly are you aiming for?

The effect given to the circles on the left, where they're less grainy in the second pic

[thomaso]

On 7/22/2020 at 10:16 PM, Samweow said:

So I posterised this image,

your code says 'threshold'. Which looks like this in Affinity, applied to your posterised sample, ... and also does what your further screenshot shows: adjust contrast within a certain area of flexible dimensions:

[firstdefence]

But this isn’t “grain", it’s pixelation, what you want is to smooth out the pixels which generally involves blur and blur loses detail.

[Samweow]

15 hours ago, firstdefence said:

But this isn’t “grain", it’s pixelation, what you want is to smooth out the pixels which generally involves blur and blur loses detail.

 

Is there a way to edit the question title?

[walt.farrell]

1 hour ago, Samweow said:

 

Is there a way to edit the question title?

If you look at the bottom of the first post, you may see an action named "Edit". If so, click it, then you can change the title.

[firstdefence]

7 hours ago, Samweow said:

 

Is there a way to edit the question title?

Another way is to long hold on the title, so click and hold the mouse button on the title for more than 2-3sec it should then become a text-box. If you hover over the title it will show a tooltip to this effect.