No high pass filter on black and white image ?

[Nadar]

 

 

Hello everyone

 

 It seems that the high pass filter does not work on a black and white image.

Well, I mean a black and white picture made from a color one in Affinity.

 Is it true ?

 If yes, is there another way to improve the sharpness ?

 

Thanks

[Alfred]

The High Pass filter works for me. How did you do the conversion to black and white? What was the colour space (RVB/8, LAB/16, etc) of the original image, and what is the colour space of the converted image?

Do you get a different result with the Clarity (« clarté ») or Unsharp Mask (« masque flou ») filters?

[Nadar]

Hi Alfred

 

on a non-raw picture with what is called "réglages" in French (square with 3 points) I selected "black and white" 

Then when I select the high pass filter : the picture appears as it is and not all grey as it should be.

[Alfred]

Look at the Layers Studio. When you add a black and white adjustment, an adjustment layer is added on top of the original image layer. That new layer is initially selected, so when you use the High Pass filter it is applied to the adjustment layer instead of the image layer. Select the image layer in the Layers Studio before choosing High Pass.

[Nadar]

Thank you Alfred  

 

I did that.  

But the all grey high pass filter image remains the same after I selected linear brightness option.  

[Alfred]

Here’s what happens for me:

[Nadar]

As you can see I only have 2 :

 the black and white ajustement layer and the grey high pass layer but not the original image background layer…

[Alfred]

I duplicated the original image layer so that I could apply the High Pass filter to the top copy and apply a blend mode (Hard Light) to get the sharpening effect. I think you can do it by nesting, but I find the ‘duplicate layers’ method more intuitive.

[Nadar]

Ok. That is the explanation : to duplicate the original picture.

What do you mean by "nesting" ?

[Alfred]

This is ‘nesting’, also called ‘clipping’:

I dragged the photo layer and dropped it to the right of the rectangle layer when the blue line was displayed. Here is the result: