Paste straight into RGB channels

[Ruzeen]

I'm not entirely sure if this already exists but I've tried it several times. 

I'm an astrophotographer and in my editing flow I'm often manipulating individual RGB channels, compositing and then re-inserting them in. Or just adding in totally different images to RGB channels. So far I have to make a spare channel, name it. THen make a new white layer, then go in and load that spare channel into R, G or B. I think this is a really convoluted method where as in Photoshop you could literally click the channel, and hit paste to put the photo into the channel. 

If this already exists and I'm doing it wrong please inform me. But otherwise I would enjoy seeing this. 

Thanks

[Great Big Bite]

I'm here to give similar feedback. As a Photoshop power-user, I would use channels religiously. Copying and pasting channels into Alpha/Mask, and directly manipulating channels to create complex masks quickly.

Would love to be able to make levels adjustments to mask and alpha channels after cutting and pasting from an RGB channel. Have found a work around, but it's not quick or intuitive.

[Stub Mandrel]

Hello,

I'm an astrophotographer too. I produce narrowband images at different wavelengths as 16-bit mono images. I typically have three of these as registered 16-bit mono  images.

I'm used to assigning these to RGB in Photoshop by pasting the mono data into each channel, but for some reason when I do this in Affinity the data gets pasted into all three channels, even if I have edit protected the other channels.

In Paintshop Pro I use 'combine channels'.

Can someone explain how to do this in Affinity, please?

[Ruzeen]

On 1/20/2021 at 9:35 PM, Stub Mandrel said:

Hello,

I'm an astrophotographer too. I produce narrowband images at different wavelengths as 16-bit mono images. I typically have three of these as registered 16-bit mono  images.

I'm used to assigning these to RGB in Photoshop by pasting the mono data into each channel, but for some reason when I do this in Affinity the data gets pasted into all three channels, even if I have edit protected the other channels.

In Paintshop Pro I use 'combine channels'.

Can someone explain how to do this in Affinity, please?

The only way I've found to do this so far is like so

Edit say your Red channel on its own instance. Then copy paste that into a new canvas. Go into "Channels". Right click "pixel gray/red" (depending on whether the canvas is RGB or grayscale). Click 'Create Spare Channel'. Name that spare channel Red.

Do that for your G B channels as well. Until in your channels window you have "RGB" in your spare channels.

Create a white layer. Make sure your image mode is set to RGB (Document > Assign ICC Format - RGB/16bit).

Click the white layer. Go to your Channels. Right click the Red spare channel and select "load into Pixel Red", and do the same for GB. Then you'll have a RGB image from your mono images. Same applies for HSO narrowband imaging too.

Hope that helps. I'll be making a tutorial soon on my astrophotography YouTube channel about doing this.

[Bob11746]

 I am having similar issues with the color channels.  I am also doing an astrophotography application, and I find the manipulation of channels non-intuitive.  I deselect the other colors, and edit only a single channel.  I can paste something in, and it will paste across all channels.  I even take a monochrome grayscale image, and copy that into a single channel but it appears across all channels.  If I do curves, unless I select a particular color, the curves affect all channels, regardless of the edit lock. It should not be so complicated to copy something to a single channel, it should not be so complicated to lock a channel, it should be straight forward.  Simply put, it doesn't work and needs to be fixed.

With curves, I cannot apply another curve over a previous one without merging first.  The old one pops up and resets.  If I want history, and if I merge each curve input, I end up having a gazillion pixels layers, taking up unnecessary hard drive space. 

In another case, I started with a new canvas, and took out a paint brush.  For some reason, it would not paint.  I did a simple screen capture and pasted it in.  The screen capture was smaller than the canvas.  The paint brush would only paint over the pasted in screen shot.  What gives?  What am I doing wrong??

All this is non-intuitive.  I thought this was a good alternative to Photoshop.  If these simple things aren't fixed, I may have to go back to Photoshop.

Bob

[Bob11746]

Ruzeen,

I have tried this and maybe I am just not that bright, but I could not get it to work. 

Can you be more specific when you say create canvas and then create spare channel, on which canvas, the new one, or the old one? When you say create new canvas, then go to channels, then right click Pixel gray/red, am I creating an RGB canvas, and then why would it say gray/red?  Nothing seems to work as you say.  When are you creating this video?

Thanks,

Bob

[Jpx]

Has this thing been fixed yet or not?

It's not acceptable for an image editing app that wants to compete with Photoshop to lack such a basic and useful feature indeed! Straightforward and intuitive channel manipulation is mandatory! 

[James Ritson]

Hi all, @Jpx, @Bob11746, @Ruzeen, @Stub Mandrel, @Great Big Bite,

I would recommend a different approach for compositing astrophotography monochrome channel data, as it's more flexible and non-destructive. The channels approach is doable, and we are looking at revising channel manipulations to improve the behaviour of pasting image data in, but I would still very much recommend the following method because it allows you to easily make direct edits to each greyscale data layer individually. This is one of the areas where translating existing workflows from Photoshop doesn't really highlight the benefits of using Affinity Photo.

Paste your greyscale layers into the parent document (which should be in RGB/32)—this would automatically be created for you if you have stacked your data directly within Affinity Photo. Alternatively, if you have opened up a pre-stacked TIFF or FIT file it may be in Grey/16. In this case, go to Document>Convert Format/ICC Profile and change Colour Format to RGB/32, then click Convert.

Once your data layers are pasted in, add Recolour adjustments (Layer>New Adjustment Layer>Recolour) and clip them into each layer. For red, leave the hue at 0. For green, set hue to 120, and for blue set hue to 240. To clip layers into other layers, click-drag and offer them to the text or label of the layer you want to clip them into.

Now select the parent data layers and set their blend modes to Add. You could probably also rename them to stay organised (e.g. R, G, B, Ha, OIII, SII etc).

You now have your composited broadband/narrowband data mapped to red, green and blue channel data. The benefit of doing it this way is that you have much more control over your separate data layers. For example, if the Ha signal is too overpowering, add a Levels adjustment, clip it into your Ha data layer and move the Gamma slider to the right slightly. You can do the opposite (move Gamma to the left) if you want to strengthen OIII or SII data. You may want to denoise a particular data layer, or increase its detail using a live Clarity filter—feel free to manipulate your individual data layers any way you want without having to pull them out into a separate document then copy/paste them back into a channel.

You can also do this with a Luminosity data layer (where you would paste it in at the top and set its blend mode to Luminosity). Add a Levels adjustment and use the Gamma slider to control the luminosity strength.

I would recommend watching my official tutorials on astrophotography editing, since they will cover a wide gamut of techniques and workflows. They all use this non-destructive recolour technique rather than pasting greyscale images into separate channel data. You can see the playlist here: https://youtube.com/playlist?list=PLjZ7Y0kROWit-4cZY2A-tiEsYaWzWQoIC

 

 

Hope that helps!

[Paul010156]

Hi James

I have an RGB image of the Rosette Nebula. I was using only the Optolong L-enhance filter. I wanted to create a pseudo Hubble Pallet Image and watched a Youtube video showing a technique using Photoshop. Basically this involved the creation of 3 x greyscale 16 bit doc and a single RGB 16 bit doc and copying combinations of the original colour channels representing Red H Alpha, Green Sulphur and Blue Oxygen. Easy to follow but when using affinity to say copy the green channel image only of the original image and pasting it into one of the other empty docs it consistently pastes the image representing the red channel despite only selecting green channel in the channels panel. Does the copy and paste option not copy only the selected colour channel or am I missing a subtle setting?

Paul

[rfpuyana]

Just bought Affinity 2 for starting to leave photoshop for good. Just realized that pasting on channels is not possible which is the base of what I do.