Enhance Per Channel Contrast

[X-Ray]

Hi,

I have been a Photoshop-User since ages, stuck with CS6 (last version without obligatory subscription).

I ran the 7 days test drive with Affinity Photo 2 and I'm impressed.
One thing that I missed were the Auto options for levels and curves (Especially "Enhance Per Channel Contrast" but also "Enhance Monochromatic Contrast" and "Find Dark & Light Colors").

I know that this processing can be done manually; e.g. for the channel contrast, I have to choose the channel, move the sliders, choose the next channel, and so on. A one-click solution would save a lot of work.

I found a 9 year old posting where this was asked; maybe this feature has been added since? Did I overlook it? Or would that be a feature request?

 

Edited June 18, 2024 by X-Ray
Typos

[GarryP]

Welcome to the forums @X-Ray

I haven’t used Photoshop since it was distributed on floppy disk so I don’t know how it works these days, but have you tried using the Auto Filters while, optionally, having the edit-ability of some channels switched off?

See attached video where you can see the functionality being used but the result is deliberately exaggerated for effect.

[X-Ray]

Thank you; yes, those Auto Filters are nice and actually what I'm looking for, but I haven't found a way to modify the curves before the filter is applied.

[Ldina]

@X-Ray 

1. Curves Adjustment Layer, then click on the "Merge" button in the Curves dialog. This will merge the Curves adjustment layer into your pixel layer.

2. Then, Use the desired Auto Filter.

If you don't want a destructive edit, use a Curves Adj layer as before (but without clicking on Merge). Then Layer > Merge Visible (shortcut, Shift-Opt-Cmd-E on Mac), which will copy a composite image of all visible layers and merge them into a new, single, consolidated pixel layer, to which you can then apply an Auto Filter. Your old layers will remain intact should you wish to revisit them. 

[X-Ray]

Thanks! I can't try this out since my trial is over, but I will when I decide to buy. 👍🏻

[X-Ray]

In the meantime, I have bought the Affinty Suite and can therefore continue to try things out.

Now I realise that I have expressed myself incorrectly:
By "modify the curves before applying the filter" I meant the following:

Example: I apply the Automatic white balance to an image.
To do this, I click on the Auto filter "Automatic white balance". The image is updated immediately and I can't check anywhere which colours have been adjusted and how.
I would have hoped that the curve dialogue with the individual colour curves would appear at the changed point. This would not only provide detailed information about the changes, but would also allow them to be adapted directly or delete them.

But that is probably not possible?

[carl123]

21 minutes ago, X-Ray said:

To do this, I click on the Auto filter "Automatic white balance". The image is updated immediately and I can't check anywhere which colours have been adjusted and how.

That brought back a few memories from 2018/19

 

[X-Ray]

59 minutes ago, carl123 said:

That brought back a few memories from 2018/19

Oh yes, indeed, thanks for pointing this out. Ultimately, it doesn't matter whether it's "Auto Contrast" or "Automatic White Balance"; the possibility of the non-destructive immediate tuning of such adjustments would generally be a great thing.

So this has not been possible for years, and there is no hope of realisation?

[Ldina]

3 hours ago, X-Ray said:

I can't check anywhere which colours have been adjusted and how.

Very true. These "auto filters" are quick auto-actions, designed to run on a pixel layer, and when run, they physically change the RGB pixel values of that layer (a destructive edit). I rarely use these Auto Filters (I can't remember the last time, actually). I don't see that changing anytime soon, if ever (for me, or in the program itself). 

If you want to adjust WB manually, or with a picker, you can use a Live WB Filter Layer. You can see what's been done, in both the Develop Persona and the Photo Persona. If you have a portion of the image that you KNOW should be dead neutral, you can use the picker to select a single pixel (or 'Option - drag' with your mouse to select a region of neutral pixels, which will average them and force the average to be neutral). Alternatively, you can use the Color Temp and Tint Sliders, but that adjustment is by eyeball. You can also use the color samplers in the Info Panel to identify, white, black, neutral or other pixels in your image and refer to the readout in the Info Panel while making adjustments. The Sampler points can be set to RGB, LAB, CMYK, HSL, etc, so pick the one that makes most sense for what you are doing. Lab and RGB sampler readouts are good for quickly assessing color casts. These Live Filter edits are non destructive and allow you to delete or change settings at any time. Non destructive edits are almost always my preference. 

If using destructive edits, you may wish to do so on a duplicate layer so you have an unaltered original as a backup.

[R C-R]

7 hours ago, X-Ray said:

I can't check anywhere which colours have been adjusted and how.

You can get a very rough idea of what was adjusted by checking the Histogram panel as you apply one of the auto filters, but there isn't a way to get more than that. As has been mentioned, they are really useful only for quick & dirty corrections.