Setting DeviceProperties using imaq.VideoDevice

Hello all,

I am doing some machine vision code where we use step to acquire frame from a camera and then process them before stepping to the next frame. We use vid = imaq.VideoDevice to engage the camera.

I can easily set some properties, such as ROI but using the commands

set(vid, 'ROI', [1 1 640 240]);

ROI can be seen under the Properties when I simply call "vid".

However, I am not sure why I can't set other properties. I can call vid.DeviceProperties and see a long list of properties that we need to change, including binning and particularly VideoMode. However, when I call

set(vid, 'VideoMode', 'Mode7');

I receive the error

Error using imaq.VideoDevice/set (line 469) No public field VideoMode exists for class imaq.internal.VideoDeviceInternal.

How can I set the vid.DeviceProperties from my code?

Thank you in advance, Quentin

Answer 1

[Andrew Davies]

You can do it with handles.

For example: vid = imaq.VideoDevice('gentl',1);

vid.DeviceProperties.AcquisitionRecordTriggerMode = 'On'; vid.DeviceProperties.FrameStartTriggerSource = 'Line1';

To see what handles you can change:

vid = imaq.VideoDevice('gentl',1); vid set(vid)

Answer 2

[Shankar Subramanian]

Hi Quentin,

DeviceProperties is a separate object representing device specific properties and you can perform set operations on that to set the property values.

As an example:

deviceProps = vid.DeviceProperties;
set(deviceProps, 'VideoMode', 'Mode7');

The above should work.

HTH,

Shankar