It's a timed slide show, why don't we optimize
Posted 10 October 2013 - 10:09 PM
In long exposure video imaging, a lot of time is used in displaying redundant information (repeated video frames with the identical information). It is necessary in NTSC analog video to satisfy the transmission and display of video.
In our case, it's more like a timed playback (at a fixed frequency) of still slides, as if it's a slide show.
Capture and store in such case can be simpler to save storage space and can afford to use better compression method designed for still image to preserve image quality, as oppose to use compression algorithms designed for video (continuous changing.)
Of course, the timed capture interval should be reasonably close to the actual long exposure time (e.g., every 8.5 seconds), and does not need to be perfectly in sync.
Using the 8.5 second (256 frames, 255 of them are repeated/redundant) long exposure as the example, a 85 second session will just yield 10 or 11 captured images.
For displaying, it does not need to be a delayed event (wait until the entire session to complete) but just to display immediately, refreshed with a new (the next) image every 8.5 sec.
What do you think?
Posted 11 October 2013 - 06:07 AM
Posted 11 October 2013 - 10:36 AM
Similar principle applies for the viewing: instead of staring at the "same and repeated" frame with poor singnal-to-noise ratio, why don't you stack them and process them on-the-fly to improve the image quality.
Why don't we optimize the presentation of already collected data for even better viewing?
Posted 11 October 2013 - 03:57 PM
Posted 12 October 2013 - 04:15 PM
Posted 12 October 2013 - 07:03 PM
I did an experiment by using AMcap (using USB video dongle to capture). I install a free software "AutoHotKey", focus on AMCap window, set the still capture folder name. Then run the test script I just created (Test1.ahk) The script looks like this
; then upload this file to Google Drive (your own code here)
Sleep 8500 ; Wait 8.5 seconds.
Every time I press the "Windows Logo" and "Space bar" keys simultaneously, it will capture 10 still images, sequentially 8.5 seconds apart.
Individual captured file will one by one showing up in my Google Drive (or ImageShack site, etc.)
Other viewers probably can run a script to see if a new file arrives in that "shared file repository site". The new one will be fetched, replacing old ones, and displayed onto the viewer's own computer.