Channels

[DannyBCreative]

I can't seem to find any info on this and so far I can't get it to work, so I'm going to presume it's not possible, but.... If someone can enlighten me, I'd be happy to be wrong.

Is it possible to copy an image into a single RGB channel as you can do in Photoshop? 

To be specific, I want to copy three separate texture images into the Red, Green and Blue channels (one for each). In Photoshop this can easily be done, and I was hoping it could also be done in AP, but so far I can't make it happen.

Any help would be great!

Thanks!

[ac-13]

Among the original set of Affinity Photo tutorials, there were several on the subject of Channels. The tutorial on Channel Packing might be helpful for your query.

https://forum.affinity.serif.com/index.php?/topic/10119-legacy-official-affinity-photo-desktop-video-tutorials/&do=findComment&comment=43458

 

[DannyBCreative]

1 hour ago, ac-13 said:

Among the original set of Affinity Photo tutorials, there were several on the subject of Channels. The tutorial on Channel Packing might be helpful for your query.

https://forum.affinity.serif.com/index.php?/topic/10119-legacy-official-affinity-photo-desktop-video-tutorials/&do=findComment&comment=43458

 

Thank you, this is useful. Though it does sort of work, I wonder if there is a shorter workflow. For example, in PS, it's literally copy/paste and you're done. I copy the image (in full color, not greyscale) from one document and just paste it into the desired channel. I then repeat that for the remaining two channels and I'm done. This AP workflow seems a bit wonky, though I am happy to know it's possible. I'm not getting the same result as I do in PS, but I'll keep investigating. Thanks again!

[Lisbon]

7 hours ago, DannyBCreative said:

I want to copy three separate texture images into the Red, Green and Blue channels (one for each)

One possible way:
1) Load the 3 images into a stack (File > New stack)
2) Ungroup the stack (Ctrl+Shift+G) and sort the layers so that, from top to bottom you have Red, Green and Blue corresponding layers
3) Run a macro to merge the layers

Merge RGB to Layer.afmacros

[jaedee]

 

[DannyBCreative]

I'll post a video showing the workflow in Photoshop, which demonstrates what I'm trying to do. Hopefully this will explain it better.

[DannyBCreative]

1 hour ago, jaedee said:

 

Thank you, but this is not what I'm trying to do. I'll post a video that will hopefully better explain my goal.

[DannyBCreative]

I made a video which shows the process in Photoshop. I hope this better explains what I'm trying to do in AP. Thanks!

 

 

[walt.farrell]

28 minutes ago, DannyBCreative said:

I made a video which shows the process in Photoshop. I hope this better explains what I'm trying to do in AP.

I'm afraid that in Photo you do it like James showed in the legacy Channel Packing tutorial. The section roughly 6 minutes in may show the simplest approach.

[DannyBCreative]

4 minutes ago, walt.farrell said:

I'm afraid that in Photo you do it like James showed in the legacy Channel Packing tutorial. The section roughly 6 minutes in may show the simplest approach.

Thank you Walt. This was my fear as well, though I was really hoping that I was missing something. I'm trying so hard to replace PS with AP in my workflow this year, but I keep running into small brick walls. Although they're small, they tend to add up. Still holding on to hope though.

[Lisbon]

1 hour ago, DannyBCreative said:

I made a video which shows the process in Photoshop. I hope this better explains what I'm trying to do in AP.

I never imagined that you were trying to merge images with different aspect ratios.

My method is a completely different workflow, but the end result certainly looks close to Photoshop.

[DannyBCreative]

16 minutes ago, Lisbon said:

I never imagined that you were trying to merge images with different aspect ratios.

My method is a completely different workflow, but the end result certainly looks close to Photoshop.

The aspect ratio is really not important for the source images and only matters for the final output. My main image has a square aspect ratio, in this case @ 2k resolution. I'm only copying the textures into the channels of the square image to produce a dirt map, so the more chaotic, the better. Using the video that James made on channel packing, I was able to achieve a similar result, but the process takes considerably longer and has more steps, which is what I was hoping could be condensed.

That said, what is your method?

[Lisbon]

2 hours ago, DannyBCreative said:

That said, what is your method?

1) Load the 3 images into a stack (File > New stack)
Uncheck all boxes regarding alignment.
2) Ungroup the stack (Ctrl+Shift+G) and sort the layers so that, from top to bottom you have Red, Green and Blue corresponding layers
At this point, you can align your layers. I used the align options provided by the move tool.

3) Run the macro that i provided previously.
4) Crop

This was my final result.

Hope it helps.

[DannyBCreative]

Not bad. Thanks! I noticed that there are 14 steps in the macro and that you use the procedural color filter. Would you mind explaining the process in a bit more detail? I like how it works, but ya gotta admit, without the macro (which is great) this would be a lengthy process. Still, I'd like to know more about how you came up with this.

[Lisbon]

Certainly Danny.

16 hours ago, DannyBCreative said:

I copy the image (in full color, not greyscale) from one document and just paste it into the desired channel.

The only way you can paste a color image (3 channels) on a single channel is by removing its color. If you remove the color you end up with just the lumminosity.
The command for luminosity is rgbtoi(R,G,B).

Lets apply a procedural texture to the "Red layer".
Note that i replaced the red channel with the luminosity of the "red layer" and the green and blue channel with white (Value 1).

For the "Green Layer" the procedural texture will look like this.
Notice that there is a pattern. For the respective channel (Green layer > Green Channel) i fill with luminosity. The rest I fill with ones (pure white).

I will skip the blue channel.

Now, if you change the blending mode of the red and green layers to multiply you will get:

After this you just have to merge the 3 layers.

To summarize, the macro applies a procedural texture to the 3 layers. Changes the blending mode of the first two to multiply and merges all layers.

Hope this makes sence.

[DannyBCreative]

Thank you. Wow, this is wild. I have never used the procedural texture, how did you even know what this formula was? This is great, but so complicated, how or where does one go to learn what these commands are? Thanks again for this explanation, or voodoo... whichever fits best.

[Lisbon]

15 minutes ago, DannyBCreative said:

how did you even know what this formula was?

I learned this formula here on the forum through another user ( @NotMyFault )

17 minutes ago, DannyBCreative said:

This is great, but so complicated

I agree. It requires a little patience.

18 minutes ago, DannyBCreative said:

how or where does one go to learn what these commands are?

There is the help file. But, unfortunately, the help file is not complete. There are commands that do not have any description.

[DannyBCreative]

Thank you for all of this. Although what you've provided is amazing, I'm a little concerned at the lack of documentation about these tools. I mean, if Serif wants AP to compete with the "industry standard" alternative, these things need to be taken into consideration. I think AP is great, and has some nice features that Adobe can learn from, for sure, but PS sill remains significantly more efficient and that can make or beak an experience.

Thanks again, really amazing work.

[RichardMH]

You can also do something similar to the above using Apply Image.

[Lisbon]

17 minutes ago, DannyBCreative said:

Thank you for all of this. Although what you've provided is amazing, I'm a little concerned at the lack of documentation about these tools. I mean, if Serif wants AP to compete with the "industry standard" alternative, these things need to be taken into consideration. I think AP is great, and has some nice features that Adobe can learn from, for sure, but PS sill remains significantly more efficient and that can make or beak an experience.

Thanks again, really amazing work.

Youre welcome Danny.

[NotMyFault]

There is a simpler non-destructive method possible

1. Place first image into file.
2. add channel mixer with settings: red 100%, green 0, blue 0 (only letting red, knocks out green/blue to 0)
3. place 2nd image, set blend mode to add
4. add nested channel mixer, filter green
5. add 3rd image, set BM to add,
6. add nested CM, filter blue
7. adjust images (size, rotation, …) if needed
8. merge visible when happy with result

• you may need to group the individual images to get BM correct.
• allows you to stretch / adjust every stock image with live preview of final result
• color formats will be automatically converted to target document  
• works in all Apps (Designer, Publisher) and on iPad
• no macros required
• In Photo, you can save presets for the channel mixer adjustment to speed up usage.

note: this recipe does not include rgbtoi, but the weights can be set in channel mixer accordingly to achieve same result.

[NotMyFault]

i just checked, rgbtoi uses ITU-R 601 for conversion

 

Y′=0.299R′+0.587G′+0.114B′

use these factors to convert colored source images into greyscale 

[DannyBCreative]

Thank you, @NotMyFault but I wasn't able to make this work with your explanation. Perhaps I misread something.

That said, I find this process in AP to be a bit overly complicated, and the lack of documentation on tools in the app is concerning. Although I appreciate all the help in this forum, the fact that users need to rely on forums to get secret information, commands, or instructions on how to use tools or achieve results that are so easily achieved in PS just reinforces the notion that AP is not ready for prime time yet. It's a major delay to have to not only look these things up in a forum, but when the solution takes a considerable amount of time and complexity, this slows production, and ultimately hurts business. I'm holding on to hope, but this year looks like it won't be the year I move it all over to AP. Maybe next year.

Thanks again for the suggestion. I do appreciate your time.

[NotMyFault]

Attached you find an example with 3 images packed into RGB channels, using the rgbtoi factors.

You see a women, a boy, a pole in the channels.

took me 3 minutes to create. Screenshot differs from final result, using different weight factors.

 

channek packing w 601 factors.afphoto

[NotMyFault]

1 hour ago, DannyBCreative said:

That said, I find this process in AP to be a bit overly complicated, and the lack of documentation on tools in the app is concerning.

Well, there are often multiple ways, and it could take many tries to find the best one.

My recipe was from memory, without time to test it and eliminate redundant steps.

Once you apply it to the first channel, it is almost mechanical, easy to remember and apply to the other channels.

i agree that AP requires a steep learning curve, especially coming from PS. But using this as argument against AP is a bit unfair: switching from AP to PS would cause similar pain. And a big plus for AP is the great forum who reacts really fast in most cases. So I would be happy to have you with us 😉