How can I reduce delay when using timer for capturing 'video' from webcam?

Ron Sofer

2020 2 13

0 个回答

6 次查看（30 天）

0 个投票

I am trying to make some sort of game which involves the use of the webcam - and i need to get live feed from the webcam - process some of the frames and also display the video I recieve (with some added plots on the image therefore preview is not an option, also i need to flip the image...).

My thought was that if I'll use timed snapshots (using timer) I will recieve a steady fps displayed and will not have to worry about my processing taking long time, but in practice I found out that even with no processing at all - only displaying the images and plotting using timer the program generates a delay.

At the first few seconds it is not noticable but after 10 seconds there is a slight delay, and waiting 10 minutes cause a delay of a second or more.

Anyway my setup for the timer was:

StartDelay 2, Period 0.05-0.3 (tried some values in this range)

ExecutionMode- tried all of them but thought fixedRate should be the best for a steady fps.

BusyMode - drop.

some StartFcn, and a not to heavy to process TimerFcn.

also I was trying to pass a complex structure of data using the UserData field, including the camera, and some state field for the display options.

Would really appreciate some help on this - I haven't found anyone using this method - maybe I was wrong to use it in the first place.

Also, I would like to know if there is a better way to process live feed images and display them other then loop snapshots.

Thanks for the help.

2 个评论
显示无隐藏无

Geoff Hayes 2020-2-14

Ron - are you saying that the longer you run your app, the greater the delay in displaying the image (from the webcam)? Could you share a small sample of your code (that demonstrates this behaviour) and in particular, your timer callback?

Ron Sofer 2020-2-15

Thank you for your fast reply and for the willingness to help out!

Yes, the delay increased through time.

Anyway, I have just discovered a fix to my problem was using a video player instance and the step function instead of imshow each time the timer tick which fixed all of the problem.

请先登录，再进行评论。

请先登录，再回答此问题。

Follow Question