RGB combination and same size requirements

Hi Sara,

I have fallen foul of this a few times now..... I stack my RGB and register them and because of dithering movements, other reasons the lights are not aligned up perfectly and so are a few pixels larger on one side than the others... then they won't combine.

Yes, normally, this would always be the case. To combine multiple channels they need to be aligned. Is registering the channels and saving them awkward or would you prefer that it is an automated task at the start of the RGB combine tool. I am sure I can fix that. If the tool finds that the channels aren't aligned, it would ask the user to automatically align the channels. Should be nice to add it I think, so it's on my priorities list.

I would far rather have it so that they combine regardless of size and then I can crop afterwards. Especially as when I was trying to batch crop the other day, APP kept using the wrong image for me to do the initial crop with... please let me decide when I want to crop after RGB combination!

I don't think I completely understand  why you are referring to cropping related to the RGB combination. Cropping will not ensure that the data is aligned for an accurate and good composite as you most likely know 😉 so I don't think I completely understand you here. APP's check for the same image dimensions of the images that yoy load in the RGB combine tool, as this is an easy check to know that images aren't aligned and warn the user about this.

To be clear about registering the channels. If you register them and save them in 4), the channels are aligned as good as they can and they will have exactly the same image dimensions so you can load them into the RGB combine tool. This step can be automated as I suggested earlier, so I'll work on that 😉

Cheers,

Mabula

Hi Mabula, The separate RGB channels are aligned, but due to various things and movements, they are not all the same size - I have some that have rotated a little etc...... and in the lower console the size is different by a few pixels as well.

I guess what I am saying is that I'd welcome the RGB combination (of registered images of course) despite the size of the individual stack. Yes it will be messy around the edges, but that'w when I want to crop, not before.

So to be clear.... ALL of my stacks are registered and saved.... all is well until the point that I want to combine registered images of different sizes.

Hi Sara,

The separate RGB channels are aligned, but due to various things and movements, they are not all the same size - I have some that have rotated a little etc...... and in the lower console the size is different by a few pixels as well.

Yes, I understand, the reason for the channels to have different image dimensions would be a different composition Field of View for the channels, and that would always imply that the channels aren't registered to each other directly I think.

So even if you create the separate channels using one and the same reference frame (for instance the best H-alpha frame) you don't have the guarantee that the channels are registered to each other due to the full composition mode. If you were to load 30 OIII frames with the Ha reference and use the full composition mode, then depending on the data certain X and Y offsets are added/subtracted to/from the field of View, so the Field of VIew contains all OIII pixels of all OIII frames. Only if you use the reference compostion mode, you would have the guarantee that the final integrated channels are perfectly registered to each other.

So I think the solution would and should be that the RGB combine tool solves this issue automatically, right?

Mabula

If you think that will work then I agree with you!!! You've left me confused! I assumed that a registered integrated stack when registered to another one meant that they were registered and that was that... now I have no idea 

Hi Sara,

I am a bit confused myself now actually 😉

It would probably help a lot if you can show me directly why the RGB combination and the registration of the channels is not working that well for you. I am currently guessing how you end up with stacks that that should be registered to each other but still have different dimensions... that shouldn't happen in APP.

If APP registers data, a field of view is created in the composition module. And all data is projected in that field of view with the same image dimensions. If it doesn't I need to know 😉

Mabula

Please see my other thread Mabula - I've attached some screen grabs that show my issue.

Ok, I will..

Hello Mabula,

Recently, I tried my first Mosaic project in APP.  I was able to get all filter channels (LRGBHa) combined into individual mosaics.  Then I loaded each mosaic (5) into the "Combine RGB" tool and assigned a color to each or left it as a custom color.  When I tried to calculate what I had, I saw an error message indicating that the "files are incompatible".  So I looked at the image sizes and sure enough, there were five different sizes by only a few pixels, e.g. 8716 x 6598, 8735 x 6576, 8716 x 6598, 8758 x 6529, & 8759 x  6531.  What is the resolution to this issue?  I don't see where the problem was solved with Sara.

Thank you,

Dale

Hi Dale @dalemschultz,

The solution is that you need to create a multi-channel mosaic 😉

1) LOAD -> enable multi-channel processing

2) load your mosaic panels per filter

3) register all as a mosaic, just like you created the individual mosaics

4) at 6) integrate, create the mosaics per channel (setting at the top), then you will get perfectly registered mosaics per filter which all have the same size and thus are fully compatible for a composite.

Sara's question was before the introduction of the multi-channel functionality. And then you would need to additionally register your filter integrations/stacks to make them compatible for composites.

The multi-channel/filter functionality solves this 😉

Now for the mosaics that you have, I don't advise you to register these now, since chances are very big that the result will not be good/optimal. Please try my suggested route from 1) to 4) described at the start of this post.

Kind regards,

Mabula

Thank you Mebula!

That did the trick!  now that I've been through it the first time, the process should be much easier next time.  BTW, I think your Astro Pixel Processor is the bomb!  Very intuitive and powerful.

Kindest regards,

Dale Schultz

Help!  I have a similar problem to some of the above issues concerning error messages.  I'm trying to do a LRGBHa combination from my integrated files.  When I do so, I get the error message about the images are incompatible so check dimensions and bit size, etc.  All I did was add each channel of integrated LRGBHa images (tried both fits and TIFF files) in the combine RGB tab and hit calculate.  When I initially integrated the four channels, I simply loaded the individual subs and hit integrate.  I did not manually go through the individual calibration and registering steps/tabs. I've never done RGB combine before - I only did OSC so this is all new to me.  Thanks

Paul 

@tsa120man Hi Paul, you can load the integrated panels as lights in tab 1. Then go to tab 4 and click the Start Registration button. Once done, click the Save Registered Frames button at the bottom of tab 4. The files resulting from that can then be loaded in tab 9 Combine RGB.

HTH, Wouter

Hi Wouter -  Well, it worked but the result is a terrible red and blue hued image of M51.  What adjustments do I need to make to correct to true color?  See attached.  Do I need to adjust the sliders on each channel to balance the colors?  I'm not sure of next steps.  Thanks for your help!

Paul

@tsa120man Maybe you should open a new post for this since it no longer concerns the same size requirement.

Will do.