advice on Image acquisition & near real time processing

Hi,

I have just started getting back into Matlab, perhaps rather at the deep end!

I am trying to use a webcam to log at 30fps, 10 frames before processing the 10 frames using optical flow to estimate velocity of the object passing through the frame; before flushing all the data and repeating the process.

I have successfully managed to acquire frames to avi file and then extract the frames to tiff format.

The real question: Is there a better (read quicker way) of acquiring the 10 frames from the video device, saving them to memory and processing them within Matlab without saving to disk (clearly the saving and converting just adds complexity and computational time).

Thank you in advance!

Answer 1

[Erik S.]

Hi,

Maybe you can get some ideas from this example:

http://se.mathworks.com/help/imaq/examples/barcode-recognition-using-live-video-acquisition.html

[Yale Brewer]

Thank you! Certainly a step in the right direction! It may sound stupid, but I forgot all about the in-built examples in the matlab help!

I was going to try and steer away from Simulink though, never really having had that much to do with it before, but might have to have a look into it!

Answer 2

[Erik S.]

Hi Yale,

Do you have Image Acquisition toolbox? There is a function (Matlab) called: imaq.VideoDevice Look in the documentations for it. Using this function it would be possible to stream live video I think. I think you can process it as well.

[Yale Brewer]

Yes, indeed I have Imaq toolbox, it is this I have been playing around with thus far - I think I will slow the whole lot down first: ideally the whole thing would happen online, but to start with I think it will have to be a "discrete" point based system for simplicity, before optimising it for real-time processing. I may have a go with Simulink in the mean time. Thank you!