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Hi,

I talked about it during beta.

 

I would like affinity photo to have a image / "apply image" similar to photoshop. Being able to apply a channel to a layer while changing it's blending mode.

 

I use this to :

color correct

getting much better color (natural look), its different than vibrance. much better.

better black and white
 

My whole portfolio have extensive use of this feature :
No other feature can create such colors : http://anstellos.deviantart.com/gallery/

 

ps: I try hard to get the similar result in affinity. It yet cannot do it. I find myself to go back to photoshop for this feature only. That's a shame, your soft almost tick all the boxes but this is a big one.

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I'm on the same boat. It's an expert tool. but it's a MUST HAVE. if it's not included I guess I will have to go back to photoshop. There is no substitute for apply image. I hope they do something because at the moment I cannot do an edit 100% in affinity :(

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As I've discussed in other threads, Apply Image is, in theory, a fairly simple thing to replicate in AP.  The problem is that when done on a single channel PS doesn't seem to be applying the channel as is but does some sort of preprocessing (contrast enhancement?) on the channel before it's applied.

 

If AP isn't able to reverse engineer this preprocessing then even if they provide an apply image function it's not likely to produce identical results with PS.

 

That's not an argument against having it as a feature just a warning that it may not be a trivial exercise to get exactly the same behaviour as PS.

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We already have Apply Image :)

 

It's in Filters -> Apply Image.

 

One thing that might be confusing is how to restrict it to only work on certain channels - for this you can use the Channels panel (whilst in the Apply Image dialog) - clicking the small pencils icons will restrict the apply image to the chosen channels.

 

Hope this helps,

 

Andy.

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Andy,

 

Thanks for the response but here, as I see it, are the issues with AP's implementation.

 

1. It seems that it will only apply an external image file.  A very common use of this function is to apply a layer to itself, often on just a single channel, so requiring that layer to be saved out and reloaded is a severe workflow limitation.

 

2. Doesn't changing the channel edits as you suggest modify the layer that's being applied to rather than the layer being applied, which I assume is how PS works - or have I got that wrong?

 

3. I had assumed that Apply Image gives the same result as putting one image on top of another on adjacent layers and setting the blend mode then merging the two layers.  Is this true?  My tests have suggested that it is when you apply all channels.

 

4. I have tried applying a single channel by right clicking on the layer to be applied and selecting "Create Greyscale Layer" then applying that greyscale rather than the whole image.  This seemed to work superficially but then I noticed that PS isn't doing this exactly.  The greyscale image it applies is not the pure channel but seems to have had some processing prior to application.  You can see this in PS by applying a single channel in Normal mode (which should reveal the image that is being applied) then comparing that with the pure colour channel.  They are not the same.  Do you guys have any idea what PS is doing to the channel before it's applied?

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Thank you very much Coranda for your help.

 

Regarding your comments:

 

1. You are right. If I might add, to clarify: blending (e.g. normal, darken, lighten, multiply, etc.) with a custom opacity is the usual approach. As you said, most of the time the target is a single channel.

2. If I understand you correctly, the target layer is the only one being modified, the source should be left untouched. Both, source and target, could be either a grayscale layer or a channel.

3. As far as I know this is the case, yes. To be consistent, the blending algorithm should behave exactly the same, either as layers or inside the "apply image" window. When creating a layer from a channel, the pixel values should match exactly. Please note that this is not the same as PS "Image: Mode > Grayscale", were PS makes an average of the three RGB channels in proportion 3R-6G-1B (source: "Professional Photoshop" by Dan Margulis). AP might be using another formula, though.

4. I cannot check it right now I don't have a PS available. Nevertheless, please note that creating grayscale images from RGBs in PS is performed by averaging the three RGB channels (check point 3. above). If I am not mistaken (please correct me if I am wrong), what we want is exact value match, i.e. a 100R in the red channel, when converted into a grayscale layer, should be equal to 42L in LAB (or a 100R-100G-100B gray).

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We already have Apply Image :)

 

It's in Filters -> Apply Image.

 

One thing that might be confusing is how to restrict it to only work on certain channels - for this you can use the Channels panel (whilst in the Apply Image dialog) - clicking the small pencils icons will restrict the apply image to the chosen channels.

 

Hope this helps,

 

Andy.

 

Thank you very very much Andy,

 

It works!. Unfortunately, as Coranda said, requiring a layer to be saved out and reload is a severe workflow limitation. It would be perfect to be able to to select as source a channel or a layer (in addition to load an image from outside).

 

Would this be doable?

 

Thanks again  :)

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We already have Apply Image :)

 

It's in Filters -> Apply Image.

 

One thing that might be confusing is how to restrict it to only work on certain channels - for this you can use the Channels panel (whilst in the Apply Image dialog) - clicking the small pencils icons will restrict the apply image to the chosen channels.

 

Hope this helps,

 

Andy.

 

 

Thank you very very much Andy,

 

It works!. Unfortunately, as Coranda said, requiring a layer to be saved out and reload is a severe workflow limitation. It would be perfect to be able to to select as source a channel or a layer (in addition to load an image from outside).

 

Would this be doable?

 

Thanks again  :)

 

I think I said that it works too fast.

 

Although an external image can be applied to a layer in AP, it does it in a very restrictive way:

 

Suppose we have a photo in the LAB colorspace, let's call it BASE. Get a greyscale layer of the A channel. Export this layer as a Greyscale/16bit Image, lets call it A-CHANNEL; we can agree that this is a One-Channel-Only image.

 

Suppose now that I wat to substitute the B channel of BASE with the A-CHANNEL image we just created. To do this, we select in AP the B channel only (eye + pen) in the channels tab; then, apply-image (normal mode), load image A-CHANNEL.

 

No luck, the result of the operation is a solid 50% grey in the B-channel. I expected the A-CHANNEL greyscale image, that has only one layer, to substitute the B channel of BASE.

 

It seems that AP is creating dummy A and B channels in the A-CHANNEL image, with solid 50% grey, and then applying the dummy B channel to the B channel of BASE.

 

As in AP is not possible to select the channel to be applied as source, it is not possible to do channel blending. I think that even a simple channel swap cannot be done.

 

Any help will be greatly appreciated. 

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