Re: Align stack using WCS or apertures problem

Posted by asteroidguy on Oct 27, 2017; 9:12pm
URL: http://astroimagej.170.s1.nabble.com/Align-stack-using-WCS-or-apertures-problem-tp722p881.html

Dear Karen,

I tested the latest daily build with a 25k image FITS cube that I would like to align, and noticed that aligning images in 3.2.0 was much faster than in 3.2.1 db (at least a factor of 5 or more?). 3.2.1db now attempts to display every single image, while 3.2.0 skipped displaying most images (or just was so fast that the counter went much faster than the display was updating). I did not notice that difference earlier, as I processed only a smaller number of frames a few days ago.

Also, after two attempts to align the images with 3.2.1db, the resulting stack was not aligned. In a third attempt, I first increased the canvas size out of ImageJ to add empty rows above and below. AIJ 3.2.1db finished correctly then. 3.2.0 did not need this trick. I noticed that AIJ only adds empty rows in the positive y direction, but not in negative y, so I gave it more "wiggle room" manually, which seemed to solve the issue.

I understand that crunching such large image stacks is likely not the main focus of AIJ, but I wanted to let you know about this. I am processing high time resolution data (mostly with small windowed sensor readouts) that result in long FITS cubes (with small image sizes).