Activity 11
Basic Video Processing
Yay! We're down to the last blog entry - as required of course! On a more serious note, I am really looking forward to continuing this blog even after the course. I would definitely dedicate my next vacation for this.
Moving on from my vainness from the last activity let us now proceed to video image processing. :)
Oh Ehm Gie! I didn't know that today is the deadline of the blogs for final exam exemption. huhuhuhuhu
Oh well there goes my chance. But anyway, this is still my favorite subject in my entire UP life. :) For once, I felt that I am indeed becoming a practical scientist.
For the activity, luckily my roommate lend me a tennis ball. As shown below:
I hate to be generic but this is the one easiest kinematic motion that I can think of. Dropping a ball. The first thing that I did is to record a 5-second 50 fps video of dropping a tennis ball with my 44 cm white board as background. In this activity, I will try to measure the acceleration due to gravity by using my vast knowledge in imeage processing. My goal is to segment the colored ball from all the frames of the video and calculate the kinematic variables that govern it.
Since I am a FOSS fanatic, I used VLC to turn the video to series of images. [2] is a helpful blog I used to know the workaround in VLC.
I chose the following region of interest (ROI) for the image segmentation. By calculating the centroid of the blobs in SCILAB, and approximating the succession of the motion of the blobs. One can calculate the instantaneous velocity of the falling ball. From this velocity, the acceleration can be calculated as the ratio of this velocity over time.
I used non-parametric segmentation because of its versatility and accuracy in detecting the blobs as compared to the parametric method.
I would give myself a rating of 12/10 for successfully calculating the acceleration due to gravity on Earth. I would like to thank wix.com for their very nice website platform.
Reference:
[1] M. Soriano, “A11 - Basic Video Processing,” Applied Physics 186 Activity Hand-outs, 2016.
[2] https://www.raymond.cc/blog/extract-video-frames-to-images-using-vlc-media-player/