Best way to modify small parts of an image

[brucet]

Imagine you have a digitized image of an old Kodachrome slide of people at the beach.  There is considerable uneven red shift from 60 years in a closet somewhere.  Some of the subjects have deep shadows on their faces from straw hats. 

What is the best way in Affinity Photo to apply color correction to certain parts of the image, leaving others alone.  You don't want better skin tones at the cost of turning the sand cyan.

What is the best way to select out just the facial shadows, maybe feathering along the cheeks, but sharply defined at the hat brim? 

One of the tutorials deals with using a mask for brightening all but the waterfalls, but if most of the image is already bright enough, I need to make a layer of just that portion to be adjusted, but it doesn't seem to be as easy in Affinity as in PS CS5 where I can go to Quick Mask and paint the target area with red overlay mask using a soft brush tool for feathering and switch to erase to remove overlap outside of the sharp demarcation of the hat brim.  Once selected I can create a new layer, brighten, desaturate if needed to get away from garish color, and apply edge blur filter to smooth out the "pointillism effect" from low resolution in shadows, then merge it back in once I'm satisfied.  

I find that Quick Mask defaults to masking the entire frame, even if only a small part if the image is selected.  This makes my go-to technique impossible.

How would you go about it?

[smadell]

Never having used Photoshop, I’m not sure how its QuickMask works. But, in Affinity Photo the red overlay in QuickMask indicates areas that are not selected. Painting with white on the QuickMask will remove the red overlay, indicating that these areas have been selected; painting with black will remove the selection. You can also use the Selection Brush along with QuickMask, which will select and snap to edges as well. Also, if you make a selection and then activate QuickMask, the area already selected will show up without the red overlay; you can modify it inside of QuickMask, as above. When you toggle the QuickMask off, the areas that were shown without the red overlay are the ones that are selected. Except for the question of whether red overlays indicate the selected area or the UNselected area, it sounds like the Affinity Photo QuickMask works exactly as you are hoping it will.

[RichardMH]

I've also never used Photoshop. In Affinity Photo I rarely use QuickMask, preferring to mask  the layers directly. Selection tools are also useful, and the selection can be saved as a Spare Channel and loaded to any mask layer. Refine selection gives some tools that might be what you want. And don't forget Blend Ranges.

[GarryP]

In addition to the advice above, all of the Adjustments and Live Filters automatically contain their own masks (you don't need to add one).

This means that you can apply an Adjustment, or Live Filter, and then paint on the Adjustment layer (or Live Filter layer) with greyscale tints (Black → White) to say where the Adjustment (or Live Filter) will be applied.

The mask which is applied when you first add the Adjustment (or Live Filter) will be filled White, so you can Flood Fill the mask to Black and then use the Paint Brush Tool (or something else appropriate) to paint the area where you want to see the changes ‘coming through’.

[brucet]

10 hours ago, smadell said:

But, in Affinity Photo the red overlay in QuickMask indicates areas that are not selected.

Thanks.  Photoshop too.  I omitted the step of inverting the selection after applying the red overlay.

[brucet]

6 hours ago, GarryP said:

This means that you can apply an Adjustment, or Live Filter, and then paint on the Adjustment layer (or Live Filter layer) with greyscale tints (Black → White) to say where the Adjustment (or Live Filter) will be applied.

So, if I understand correctly, I would have to paint the target area in each adjustment layer separately with black in order to do color balance, brightness, saturation?  Or is there a way to apply an adjustment layer to another adjustment layer?

Still, this will be a valuable tip for images where I want to vary the effect of a single adjustment layer.  Can I apply a gradient to one of these adjustment layers to apply its correction more strongly on one side than the other?

[brucet]

9 hours ago, RichardMH said:

 Selection tools are also useful, and the selection can be saved as a Spare Channel and loaded to any mask layer. 

And don't forget Blend Ranges.

 

[brucet]

9 hours ago, RichardMH said:

Selection tools are also useful, and the selection can be saved as a Spare Channel and loaded to any mask layer.  And don't forget Blend Ranges.

Thanks.  That might solve the problem of having to select for each of several correction layer types.

What are Blend Ranges?

[Lisbon]

14 hours ago, brucet said:

One of the tutorials deals with using a mask for brightening all but the waterfalls, but if most of the image is already bright enough, I need to make a layer of just that portion to be adjusted, but it doesn't seem to be as easy in Affinity as in PS CS5

You want to brighten a waterfall...

But you dont want to brighten all the image. Just the waterfall.
So you need to invert the mask (Ctrl+I).

This got worse. We lost the brightening effect.
Back to square one.
But... if you grab a white brush and paint on the mask, over the waterfall you will get the desired effect.

What if, by mistake, you paint outside the waterfall?
Change your foreground color to black and paint on the mask.

Hope this helps.

Image: ReneGossner

[smadell]

14 hours ago, brucet said:

What is the best way in Affinity Photo to apply color correction to certain parts of the image, leaving others alone.  You don't want better skin tones at the cost of turning the sand cyan.

My answer to you regarding use of Quick Masking only had to do with the method you went on to describe. There are many (better) ways to accomplish what you seem to be trying to do. The first one that comes to mind is an HSL adjustment.

Add an HSL adjustment layer above your photo, click the red circle, then click the “Picker” botton on the HSL panel. Use the picker to choose the color (on the photo itself) that you’re aiming to modify. The hue, saturation, and luminance can all be adjusted, and will be confined to the red you have chosen. If there are reds getting altered in other parts of your photo, and you don’t want this, click on the adjustment layer (in the Layers panel) and then paint in black on the areas you want to supress the adjustment; since the adjustment layer has a built-in mask the painted black effectively masks the adjustment from showing up in that area.

Also important, after using the picker tool to select the color you eant to modify, you can change the range of the color and the feathering of the color by moving the 4 little circles around the color wheel inside the HSL panel. There should be a good James Ritson video about this that you can watch on the Serif website. It’s way easier tounderstand if you see it happen in a video!

[smadell]

To answer your other questions - here’s a good video by Dave Straker about using the HSL adjustment.  

And here is a video from Serif about Blend Ranges.

https://affinity.serif.com/en-gb/tutorials/photo/desktop/video/342752528/

[brucet]

1 hour ago, smadell said:

To answer your other questions - here’s a good video by Dave Straker about using the HSL adjustment.  

And here is a video from Serif about Blend Ranges.

https://affinity.serif.com/en-gb/tutorials/photo/desktop/video/342752528/

Thanks for your detailed suggestions and links.  I'm sure they will be helpful in making the transition from my familiar Adobe to Affinity.

[brucet]

2 hours ago, Lisbon said:

You want to brighten a waterfall...

But you dont want to brighten all the image. Just the waterfall.
So you need to invert the mask (Ctrl+I).

This got worse. We lost the brightening effect.
Back to square one.
But... if you grab a white brush and paint on the mask, over the waterfall you will get the desired effect.

What if, by mistake, you paint outside the waterfall?
Change your foreground color to black and paint on the mask.

Hope this helps.

Image: ReneGossner

Thank you for your detailed progression through the steps.  It will help greatly me to conceptualize how Affinity works so I can speed the transition.

[thomaso]

3 hours ago, brucet said:

So, if I understand correctly, I would have to paint the target area in each adjustment layer separately with black in order to do color balance, brightness, saturation?  Or is there a way to apply an adjustment layer to another adjustment layer?

These are 2 different questions, not either or, right?

1. Yes, you can paint the target area in each adjustment separately. And/or you can add a mask layer and paint the target area there & only once. Means you can use the mask of each adjustment independently + you can use a common mask for both.

2. The mask of adjustment layers is always grayscale or black&white and it does not get affected by other adjustments.
– But the layer hierarchy of adjustments matters and thus one adjustment can affect another. But you wouldn't place an adjustment to influence another because its influence on the image is larger than on the other adjustment. If you want to adjust the contrast/brightness/levels of an adjustemnt you can use its layer blend mode range curves (> cog icon next to the blend mode menu). Also you can't use a layer fx effect on adjustment layers (e.g. Blur); although the interface allows so, it gets ignored.

[brucet]

21 minutes ago, thomaso said:

The mask of adjustment layers is always grayscale or black&white and it does not get affected by other adjustments.
– But the layer hierarchy of adjustments matters and thus one adjustment can affect another. But you wouldn't place an adjustment to influence another because its influence on the image is larger than on the other adjustment. If you want to adjust the contrast/brightness/levels of an adjustemnt you can use its layer blend mode range curves (> cog icon next to the blend mode menu). Also you can't use a layer fx effect on adjustment layers (e.g. Blur); although the interface allows so, it gets ignored.

More valuable information.  Especially the last explains why, whenI tried blur and sharpen with no apparent effect; I probably had an adjustment layer highlighted instead of a pixel layer.  

[GarryP]

17 hours ago, brucet said:

Can I apply a gradient to one of these adjustment layers to apply its correction more strongly on one side than the other?

You can use pretty much any painting/colour technique you want with the built-in masks, including the Gradient Tool.
However, once the gradient is applied it will be ‘fixed/baked-in’ until you apply another one or do other editing to the mask.
Attached is an example where I have added a Gradient Fill to the Black & White Adjustment, and another (reversed) to the Voronoi Live Filter.

Note: You can only apply shades of grey but you can use colours which will be converted to shades of grey depending on their lightness(?).

[brucet]

9 hours ago, GarryP said:

You can use pretty much any painting/colour technique you want with the built-in masks, including the Gradient Tool.
However, once the gradient is applied it will be ‘fixed/baked-in’ until you apply another one or do other editing to the mask.
Attached is an example where I have added a Gradient Fill to the Black & White Adjustment, and another (reversed) to the Voronoi Live Filter.

Note: You can only apply shades of grey but you can use colours which will be converted to shades of grey depending on their lightness(?).

Thanks.

That's a stunning image you created.