Astronomy work with Krita

[JL VT]

Hello Stephen!.

My knowledge of Krita's insides is still limited, but I'll try to let
you know of all things I believe or am certain that can be done in
Krita.

On Sun, Aug 29, 2010 at 7:03 PM, Stephen Williams
<xfbbzyb4gz at snkmail.com> wrote:
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> So Krita survives the major cuts in my mind. (I'm having trouble
> getting kde4 and koffice2 compiled for my Mac, but I believe it
> is doable.) But is this really a reasonable thing for me to want
> to do with Krita? Here is some more detail:

A Mac user interesting in Krita!, This is great news  :)

> The images I work with are RGB48 from a Nikon D80 camera, so they
> are fairly large. Then I will want to build up a stack of them,
> typically a half dozen or dozen images, and also combine a few
> dark field shots. The processing would amount to aligning each
> image, adding them to a stack, subtracting out the dark-field
> images, then tone-mapping the results.

Aligning -> I haven't done this before, but aligning an image with
another based on their limits sounds very doable and simple. Even if
it wasn't supported (I doubt it) it could be done hackishly by
blitting a layer into another that's correctly aligned.
Adding them to a stack -> KisImage, the class that controls images in
Krita, is a stack, so this is doable and should be simple.
Subtracting out the dark-field images -> Perfectly doable, there are
composite operations for that.
Tone-mapping -> This is the complex part isn't it?. I've seen mentions
of High Dynamic Range in Krita's source code, but I'm not sure if the
feature is finished. I'll let someone with more knowledge respond.

> I have been thinking along the lines of importing the images into
> an image stack layer group, and the dark fields into another layer
> group. Within each layer group, it would be nice to be able to turn
> individual frames on/off.

KisImage supports turning individual frames on and off from
visibility, I think it should be simple to disable them from being
composited and tone mapped, but I'm not sure. Nevertheless, it's
probably doable.
Also, making 2 image stacks is as simple as creating 2 KisImages.

> So does this all sound doable in Krita?

This sounds doable.

> I expect to write plugins
> to do stacking and dark field correction. (And of source I/O of
> FITS files.)

I'm not sure exactly which category your plugin fits, if it is a
filter or something else. But there's a broader plugin category called
"extensions" for those that include several subplugins.
Moreover, anything that could be described as a filter will be simple
to do, as making plugins for Krita is a very straightforward task.


Thank you for your interest!.