viewing the same sub-frame of images from different FITS captures

@outer-space,

I think that APP will do what you are asking but you have to have:

a)  Registered the images

b)  In the Image Viewer have the mode set to Registered

You can then scroll thru your lights and APP will pan and/or rotate each frame to the same view as the previous.

Mike

@mestutters  Thanks, yes that would be another approach. I will still need to store the registered images on disk, right? if that is so, I am still looking for a way to not have to save extra images and, in certain cases, I want do this before processing the stack. 

Thank you,

@outer-space

I guess the need to save registered images depends on your workflow and perhaps also the volume of lights that you have to process.

I sometimes find it useful, following registration, to set my planned crop on the selected reference frame and then to scroll through the remaining lights in order to check the framing on each individual frame prior to integration.  I can then deselect any frames that do not significantly contribute to the planned final image or adjust the crop accordingly.  Obviously I can also check the frames for other obvious flaws and remove these too.

The downside of this approach however is tedium as display of each calibrated and registered frame is somewhat slow, at least on my lap-top.   (Hint, I am hoping that when Mabula starts to introduce GPU processing into APP image display will be an early candidate for attention.)   However as I tend to go for long exposures times my integrations seldom  involve more than 300-400 frames so  I find I can just about cope. Saving the register fames then reloading them as lights might make image display a little quicker as I think APP would not have to apply its image calibration and alignment on each raw frame prior to display.

I can think of no reason to save registered frames prior to integration unless I envisaged a need repeatedly reintegrate the set of subs with e.g. different integration parameters.

Hope this provides food for thought

Mike

@mestutters Yes, this is useful input indeed.

I use APP for everything. Even loading and inspecting images as the sequence capture happens. I typically like to see certain parts of the image (some cases, framing the entire DSO) or in other cases: viewing it at 100% to ensure  internal guider dithering is happening, verifying tracking of the mount,  verifying I am not getting elongated stars and so on.

For these cases (a review) its handy to load up the last 5 - 7 captured images on APP and move through them. Having them in the same (X1,Y1):(X2,Y2) rectangular region is useful in the viewer.

These are some of the reasons for this feature request.

Thank you,

@outer-space,

Hi, 

OK, your Use Case is I think now clearer.  My interpretation is that you basically would like for APP to be able to monitor an image capture directory and then as each new image (or a given small number) have been added for it  then to perform star analysis and image registration.  You could then readily scroll through and closely inspect the newly captured and registered images and reject any that do not meet your quality requirements.    I cannot see how APP can accurately display 'the same (X1:Y1), (X2:Y2) rectangle region' without first going through a registration process.

As I indicated earlier it is entirely possible to do this manually by periodically loading your newly captured images into APP and manually invoking Star Analysis and Registration. I see no value in saving small batches of Registered images at this point.   I would wait until I had a reasonably complete set of image files and then process the lot through from raw FITS to Integration and post processing.

It is not for me to decide APP's development priorities but given that most Image Capture packages provide at least basic metrics to help users assess the quality of newly captured images I cannot see this request being a high priority.

As an aside, have you ever used or looked at, for example, ASTAP?  I use it purely for plate solving but it does also support directory monitoring, analysis and even live stacking of newly captured images. Sadly I think it does not support viewing of accurately registered individual frames that I believe you are looking for.

Hope you find what you are seeking.

Regards

Mike

@mestutters 

I do not need automation of monitoring the directory. OK to manually load the 5 - 7 images I want to verify. I actually don't want to do the registration, as I want to verify the mount tracking, dithering etc over the 5 - 7 images that I want to view.

Basically, all that I am looking for is very similar to the 'batch crop' tool. Only I was looking for a 'batch view', where I can set the X1,Y1 -> X2,Y2 rectangle and as I move through the loaded files in the file list, it pulls up the same X1,Y2 -> X2,Y2 of the image --- all without needing any processing steps like registration.

This whole request is building up on the stand-alone image viewer/stretcher request earlier. Depending on the developers and how they think about it and prioritize, the request in the current thread could also be added to the roadmap.

In any case, I'll wait to hear from the APP devs.

Thank you,

I can understand the use-case, I talked to Mabula about it, but it's not something he thinks is very valuable (as in, needing a different view app). I can check if your idea of a batch view option may be interesting, I'll put it on our issue list just so I don't forget about it when Mabula returns. 😉

Sure, if a batch view option is available, it is quite generic enough that I can use it for some of the use-cases I have outlined earlier -- Moving through a selection of FITS images and being able to precisely view the same sub-region of the image(s).

Thank you for your response.