Question about imaq.videodevice/step

Greetings everyone,

I have a problem, I am trying to run live video for matlab and encountered a problem.

Error using imaq.VideoDevice/step
Too many input arguments; expected
0 (in addition to the object
handle), got 1.

Error in LiveVideoTest (line 135)
     step(Video, final);

Whereas, Video is the is the imaq.videodevice and the final is my processed image, which is in black and white. WHy it have this error on getting too much input, I only have my final image keyed in to my step function.

Thank you very much.

Regards, Akira

Answer 1

[Walter Roberson]

imaq.VideoDevice is video acquisition. It gets data from the device you configured. There is no point passing it an image.

I suspect you wanted to pass your image to a vision.VideoPlayer

[Akira Chan]

Dear Mr Walter,

so instead of putting the image, what should I put in?? A video from the camera? If so, wouldn't the captured video be in rgb mode? Because I want my output to be only white and black.

Regards,

Akira

[Walter Roberson]

acquired_image = step(Video);

is enough to fetch a frame and store it in acquired_image. The captured mode would be whatever you configured for the imaq.VideoDevice call. At worst you can im2bw() or rgb2gray() the acquired image to convert it to black and white or to grayscale.

Remember, imaq.VideoDevice is for getting frames. There are other calls for displaying frames.

[Akira Chan]

Dear Mr Walter,

Thank you for your guidance. I can now play live video on my system right now thank you :D

Regards,

Akira