Posted by
John Oreopoulos on
Jun 23, 2008; 6:57pm
URL: http://imagej.273.s1.nabble.com/Flow-tracking-tp3695757p3695759.html
My mistake, I should have written "fps" for the playback frame rate
instead of "ms". I got my units mixed up. The sentences should read:
To see the protein dynamics, it is necessary to play back the image
sequence with a 300 fps frame rate on the computer screen in ImageJ,
which is possible with the latest version of ImageJ (max frame rate
1000 fps or frame rate allowed by memory and processor speed).
I usually save image sequences as .avi files, but I've noticed that
if I do this when the display frame rate in ImageJ is greater than
100 fps, the avi is saved with a frame rate of 100 fps.
John
On 23-Jun-08, at 2:27 PM, John Oreopoulos wrote:
> Dear ImageJ listserver,
>
> I have a small problem I was hoping the community might be able to
> advise me on. I have several long time-lapse live-cell image
> sequences captured using TIRF microscopy. 1000 images were captured
> with a 200 ms exposure time and a 500 ms delay in between
> exposures. A typical image sequence file size is about 500 MB. It
> is necessary to capture many images and with this rate of
> repetition since the the cells I am imaging express a fluorescent
> membrane protein that exhibits very interesting dynamics (both fast
> and slow motions) and over a long time period. I do not have the
> option of capturing fewer images over the same time interval since
> doing so will cause the software to miss recording very transient
> and fast vesicle fusion events with the membrane. We use ImageJ for
> analysis and we run the program on a powerful Linux computer with
> 4GB of RAM. To see the protein dynamics, it is necessary to play
> back the image sequence with a 300 ms frame rate on the computer
> screen in ImageJ, which is possible with the latest version of
> ImageJ (max frame rate 1000 fps or frame rate allowed by memory and
> processor speed). If played slower than this, then it's difficult
> for the human eye to discern a fusion event and notice any protein
> motion.
> My problem is that I would like to make these movies portable for
> presentations (in Powerpoint or Quicktime for example) without too
> much compression that masks the features I'm trying to show and
> without slowing them down to a lower frame rate.
> I usually save image sequences as .avi files, but I've noticed that
> if I do this when the display frame rate in ImageJ is greater than
> 100 ms, the avi is saved with a frame rate of 100 ms. Is this a bug
> or is it simply a limitation of the .avi format, or is it a
> limitation of the player I use to playback the .avi file
> (Quicktime)? I can find no mention of a maximum frame rate in
> the .avi writer plugin on the ImageJ website.
> Even if I can save files properly with these high frame rates, I
> likely will not be able to embed them in Powerpoint and play them
> at that speed since the demands on my laptop for this file size and
> display rate are too great. Does anyone know of an alternative way
> for displaying large movies with high frame rates?
>
> Thank you for your time.
>
>
> John Oreopoulos, BSc,
> PhD Candidate
> University of Toronto
> Institute For Biomaterials and Biomedical Engineering
> Centre For Studies in Molecular Imaging
>
> Tel: W:416-946-5022