stitching together a solar mosaic ?

[glowingturnip]

Hi all,

I've not done a lot of solar stuff, but I did have a go the other day, and thought I'd try and make a full-disc mosaic.  I've got six panels (upper, middle and bottom; left & right) in white light.

Just wondering what people use to stitch solar mosaics together ?

I had a quick go with Microsoft ICE, but it wasn't liking it, I guess because there's a lack of detailed features and only the broad shape to work from.  I suppose I could try stitching them together manually in photoshop with 50% opacity (least preferred option, obviously) or see if I can do a dynamic align with PI off the sunspots (though I'm not sure all the panes have a sunspot, iirc).  Any other ideas ?

[Zakalwe]

I find that the Photomerge function in Photoshop seems to work well. You might need to calibrate the frames by using a flat in stacking. Also, merge them before sharpening/wavelets.

[glowingturnip]

cheers, will try Photomerge

flats...  ahem...  whoops, too late for that

[michael.h.f.wilkinson]

AutoStitch, every time. Free, fast, works a treat. No manual interference needed. Only drawback: exports to JPEG only (99% quality max).

 

This is a 30+ pane mosaic, click to view full size

[Davey-T]

As per Michael, AutoStitch is the only program that works every time, all the others are a bit hit and miss and very fussy about overlaps etc.

Dave

[michael.h.f.wilkinson]

Actually, I have seen AutoStitch go wrong on rare occasions, but usually it works. On Ca-K I find that MS-ICE sometimes improves on AutoStitch, but for H-alpha AutoStitch rules

[Davey-T]

Only done HA with it, still saving for CaK module

Dave

[glowingturnip]

cool, will give autostitch a go

[David Smith]

1 hour ago, michael.h.f.wilkinson said:

Actually, I have seen AutoStitch go wrong on rare occasions, but usually it works. On Ca-K I find that MS-ICE sometimes improves on AutoStitch, but for H-alpha AutoStitch rules

I will have to give AutoStitch another go, kept telling me to select multiple images or some such nonsense (I had selected 6) the last time I tried it

[michael.h.f.wilkinson]

2 minutes ago, David Smith said:

I will have to give AutoStitch another go, kept telling me to select multiple images or some such nonsense (I had selected 6) the last time I tried it

Be sure to get the newer windows 64bit version. The older 32 bit is less good

[glowingturnip]

i presume this is the link, I think you had a wrong link above ?  http://matthewalunbrown.com/autostitch/autostitch.html

[michael.h.f.wilkinson]

4 minutes ago, glowingturnip said:

i presume this is the link, I think you had a wrong link above ?  http://matthewalunbrown.com/autostitch/autostitch.html

Yes that is the one. don't know why that link got posted there, will correct it

[glowingturnip]

sadly not with Autostitch...

 

Will try photomerge

[glowingturnip]

still working away at this one.  My Photoshop Elements doesn't have Photomerge unfortunately.

 

I got this far using Dynamic Alignment in Pixinsight off the sunspots but it's still obvioulsy not quite there - think I'm going to have to nudge it manually in PS:

 

 

 

[glowingturnip]

bit of a slow burn this one, a lot of real life been getting in the way recently, so apologies for resurrecting an old thread.  So I've managed to align the panels - a complicated process of adding anchor points outside the disc for each image, aligning each by hand and eye by nudging in Photoshop Elements, taking the resultant low resolution aligned image back into Pixinsight and aligning each panel to that in hi-res.

 

 

As you can see though, I've still got blending issues along the boundaries that a stitch program would usually resolve automatically.  Any idea how I can deal with those manually ?

 

Cheers

 

[Davey-T]

In P'Shop you can set the opacity and delete edges using the eraser to remove the straight joins and play with the levels to match the "brightness"

Dave

[glowingturnip]

apologies for bumping a really old thread, but this one seemed get stuck in my processing queue and I've only just got round to finishing it.  It's a mosaic of 7 panels, in white light, from back in February:

 

In case you're wondering how I did it, I ended up totally geeking out with pixelmath in Pixinsight:

- I aligned the panels by hand in Photoshop in the end with 50% opacity and nudging them (fortunately only had transformations to deal with, not rotation or scaling).  I've only got Photoshop Express which is 8-bit, so I added align points outside the disk for each panel in PI, aligned them in PS, re-imported to PI and then aligned the original panels to the PS version with the align-points thus keeping it 32 bit

- to get the intensities to match, i used pixelmath to produce masks which were 1 where there was signal from both panels and 0 elsewhere, then again with pixelmath, averaged the intensities of each panel but only where the mask was 1, then scaled one panel to match the average intensity of the other. After this step, once all panels were correctly scaled, the joins were already nearly perfect, though you could still see join lines if you look closely

- to get rid of the join lines, I again used pixelmath to build gradient opacity masks so I could merge the panels (with pixelmath).  After this step, it was pretty much seamless.  The masks look similar to this one:

- regular processing to finish.

 

I think it's safe to say I won't be doing this again !

 

 

[Davey-T]

Sounds like hard work Stuart, with stuff that refuses  to play nice I usually just lasso  and feather the too bright or dark bits and nudge the levels.

Dave