How to harden edges of a layer. I desired to harden partially transparent edge pixels on part of a layer to create a cleaner edge at the part of the layer, how to accomplish this?

[Affinity Rat]

How to harden edges of a layer. I desired to harden partially transparent edge pixels on part of a layer to create a cleaner edge at the part of the layer, how to accomplish this?

Partially transparent selection seems to additionally select 100% transparent, requiring boolean operation to select partially transparent.

 

[NotMyFault]

In principle add a curves layer on alpha channel, and boost low/mid values.Or use levels adjustment on alpha channel, and tweak gamma, or move „white level“ slider from 100% to smaller values.

This works best when the adjustments are above the pixel layer. Nesting adjustments on alpha channels does not work reliable in many cases due to unfixed bugs or „design decisions“, and depending on layer structure.

[B0R10N]

Modifying alpha chanel with curves is completely broken on iPad for months. Once you select alpha channel, curves panel stops functioning. It was reported more than once by few users, but it seems there are far more important features requiring devs attention. No sarcasm, this is just the way it is.

I need this feature myself, but in the absence of fix I move stuff to desktop when I can.

 

 

 

 

[Affinity Rat]

I tried the curves alpha channel on my iPad mini and had no problems, however I had a very simple layer structure.

 

[B0R10N]

Lucky you! Thanks for letting me and others know.

Today I've checked Affinity Photo beta 2.5 - so it has a separate/clean config files, I suppose - and it is still broken for me. I wish I could simply reinstall stabile release to see if it helps, but moving my whole library of work files out of AP is out of the question ATM. I got too much work stuff that needs to be moved in organized manner

I'm using iPad Pro 11" 2018 with iPadOS 17.4.1

Cheers

 

[Affinity Rat]

I did notice that I cant modify Alpha channel with curves on a sRGB jpg file, but can modify RGB channels. No crash just clicking on curve doesnt do anything, no point created to modified. Channels studio, shows the correct alpha of a selection.

Of note: I you attempt to use curves to modify a file that is colour mode RGB, but attempt to modify curves using CMYK or other colour mode nothing will happen. 
 

Note 2: The user guide says you can use different colour modes with curves, I tried it and it didnt work, but after realizing the need to click the move tool first, I see it does actually work as suggested.

 

 

 

[Affinity Rat]

Back to APho file, if there is a fill color layer below the curves target layer curves does not work.

 

[Affinity Rat]

11 hours ago, B0R10N said:

iPad Pro 11" 2018

Too bad, just maybe your iPad not grunty enough assuming it has enough free memory. Upload a file I and will try on my iPad.

[NotMyFault]

4 hours ago, Affinity Rat said:

Too bad, just maybe your iPad not grunty enough assuming it has enough free memory. Upload a file I and will try on my iPad.

You are using V1 which is not affected 

[NotMyFault]

4 hours ago, Affinity Rat said:

Back to APho file, if there is a fill color layer below the curves target layer curves does not work.

 

The fill layer makes everything fully opaque.

the recording shows you have a selection active. You must deselect all before creating the curves adjustment  layer.

To restrict the curves to the pixel layer, you need to nest it to the masking position of the pixel layer.

[Alfred]

36 minutes ago, NotMyFault said:

To restrict the curves to the pixel layer, you need to nest it to the masking position of the pixel layer.

Does the nesting position matter for an adjustment layer? I can drop the adjustment layer on the thumbnail of the pixel layer to achieve mask-nesting, or drop it on the label of the pixel layer to achieve clip-nesting, but regardless of which way I do it the visual result is the same.

[Affinity Rat]

A gotcha for me when using curves in Alpha mode is sometimes I cant edit the curve, clicking on curve has no response, but if I click on the move tool and then again click on the curve I can edit the curve, dont know whats going on here.

I dont see anywhere that indicates the need to be using the move tool prior to editing the alpha curve.

 

 

[B0R10N]

15 minutes ago, Affinity Rat said:

A gotcha for me when using curves in Alpha mode is sometimes I cant edit the curve, clicking on curve has no response, but if I click on the move tool and then again click on the curve I can edit the curve, dont know whats going on here.

I dont see anywhere that indicates the need to be using the move tool prior to editing the alpha curve.

 

 

Wow, you are right! Once you open the curves panel, choose alpha channel & switch to move tool it starts working. This is incredibly weird, I would have never thought such action would alleviate this evident bug. Great find, @Affinity Rat

[NotMyFault]

8 hours ago, Alfred said:

Does the nesting position matter for an adjustment layer? I can drop the adjustment layer on the thumbnail of the pixel layer to achieve mask-nesting, or drop it on the label of the pixel layer to achieve clip-nesting, but regardless of which way I do it the visual result is the same.

Wäre now entering the old-but-never-to-be-fixed-bugs section.

any layer, including adjustments, and specifically the alpha channel of those layers, will be constraint to the not-fully-transparent areas of the parent layer, when nested to child position. When nested to mask position, it will impact the full canvas.

take an rectangle (smaller than full canvas) with black-to-transparent gradient, and nest an adjustment creating 100% alpha (curves, channel, mixer, levels), and try out both child positions to spot the difference.

and then try to zoom in / out between 10% and 450% to see rendering bugs.

Why buggy? Depending on version and layer type and groups used, it often does not work correctly, or leaves squares in black or white depending on zoom level.