What is the point of PIPP?

[Sammyb]

I have used this a little bit prior to processing in AS12. It seems to make no difference to the final image. In some cases it makes it worse.

Can anyone provide any advice as to when it is useful to run your avi's through PIPP prior to aligning and stacking?

I'm thinking I've missed something

Sam

[themos]

I think it just gives the later stages of processing less work to do because they have to look at fewer pixels (of dark sky!).

[Sammyb]

yes the aligning and stacking process in AS!2 does seem to be quicker if i run through PIPP first. There must be more than that though surely?

[JamesF]

I suspect Chris will answer anyhow, but in the main I use PIPP in two different ways:

For solar/lunar imaging I use it to convert RAW files from the camera to TIFF, to "grade" the frames so I can drop the poorer ones very quickly and to crop the images down a little and centre the target to improve processing speed.

For planetary imaging I tend to use it for dropping frames where the target is not present on the frame, or is only partially present, and to crop the images and centre the target.

Registax v6 in particular seems very bad at handling low quality frames or large jumps in alignment and whilst AS!2 can do better it's faster if it has less data to process.

James

[JamesF]

Oh, and whilst it may sound as if perhaps a minute or two improvement in the speed of AS!2 isn't worth the bother, I'm currently processing about fifty capture runs of up to 5,000 frames each from last night. That takes a fair bit of time...

James

[michael.h.f.wilkinson]

One problem I have had with PIPP (compared to AS!2) is that it does not allow dark/flat correction (I need the latter with my CMOS sensor), which must be done on un-cropped frames. AS!2 can stack just a cropped image itself (after dark/flat correction).

[cgarry]

I have used this a little bit prior to processing in AS12. It seems to make no difference to the final image. In some cases it makes it worse.

Can anyone provide any advice as to when it is useful to run your avi's through PIPP prior to aligning and stacking?

I'm thinking I've missed something

Sam

Hi Sam,

With hindsight the 'Planetary' part of the PIPP name may not have been the been the best choice as it has somewhat outgrown its original purpose, not to mention that AS!2 has arrived and certainly the later versions do much better job with tricky AVIs.

PIPP is really a toolbox of software functions for working on videos/images and how it is used is really up to the user. Here is a quick of a list of where PIPP can help, though most of, if not all of these tasks can be achieved using other programs that are available:

* Lunar/Solar imaging with a DSLR.

* Extracting the good frames from an ISS video for stacking.

* Stacking frames with large amounts of empty background sky in RegiStax.

* Stacking frames with planets moving around the frame and even the off frame in RegiStax (I have also seen examples that still throw AS!2).

* Stacking an AVI file that uses a lossless codec in AS!2.

* Reducing file sizes (and stacking time) by centring, cropping and potentially removing the lower quality frames.

For me the advantage of doing this is I can set a batch run of all my captures from a night's imaging while I do other things (like sleep). I can then spend less time actually sitting in front of the computer while the stacking program is doing its thing. I guess it depends how many captures you get in a night as to whether it is worth doing this. Also, this reduces the size of the files that I archive.

* Attempting to get a better image than a stacking program can produce on its own.

I assume that this is really what you are interested in and to be honest it is a hard thing to achieve. Even when it is achieved the difference is very subtle and only really noticeable upon close inspection. In this case I am talking about stacking 100% of the frames that PIPP selects and trying the quality weighting function. With my best quality data (not that there has been much of that lately) I always try RegiStax and AS!2 with and without PIPP doing all of the frame selection and I have honestly never seen PIPP produce a worse result than either just RegiStax or AS!2, but I have seen many examples of there being no real difference between the results. Of course for other people with different equipment and different length captures, results may differ.

One thing to note is that if the quality minimum/maximum subsample values in PIPP are too large then the fine details will be ignored when calculating the frame quality. I would imagine this could throw the quality selection off somewhat. For Jupiter, in PIPP I use Minimum Subsample Value of 2 and a Maximum Subsample Value of 3 in order to concentrate the quality selection on the finer detail. With something like Mars which I image at a much longer focal length I would leave these values at 3 and 5.

Okay, I seem to have waffled on a bit! Back to your question of when to run planetary AVIs through PIPP. If you do not use PIPP for your usual processing routine then I would suggest just trying it for reprocesses on captures taken when the seeing is good to see if you can eke out a tiny bit more detail.

Cheers,

Chris

[JamesF]

For me the advantage of doing this is I can set a batch run of all my captures from a night's imaging while I do other things (like sleep). I can then spend less time actually sitting in front of the computer while the stacking program is doing its thing. I guess it depends how many captures you get in a night as to whether it is worth doing this. Also, this reduces the size of the files that I archive.

How do you actually do that, Chris?

James

[cgarry]

I just add all the files to the 'Source Files List', set my options and hit the 'Start Processing' button. You need to make sure you are in 'Batch Mode' rather than 'Join Mode' though or you will end up with one monster AVI file!

Chris

[JamesF]

Ahhh, right. Next time I shall remember to give that a try. Should make life much easier when I'm trying to process several hours worth of video

James