Cursor overlay on Hydra VideoPortal Class object

[Copperwhite]

Hi, I have no experience with ActiveX or any of this stuff but I found a nice program on the net which uses Labview to take images from my Logitech webcam (attached). I now wish to be able to place an alignment cursor on this image, (for marking the position of a laser spot). The real-time image is in the Hydra VideoPortal Class format. Can anyone suggest anything,
Thanks, Rob

[Jon Bowers]

I am missing the image display vi but from what I can see, as this is an ActiveX control you can not manipulate directly from LabVIEW unless there is method or property in that ActiveX class that you can call. If you just want a visual representation of a cursor on the image then you could place a picture control over the display make the background invisible and draw the cursor on there.

Jon Bowers
Applications Engineer
NIUK

[Copperwhite]

Thanks for your response Jon, I have tried to place a picture control over the ActiveX control as you suggested but just like everything else, it gets moved behind the ActiveX box. Is there anything I can do to stop this happening, as this solution would do fine if I could make it work!
Rob

[Jon Bowers]

Hi Rob,

Your right I have just tried this and it won't allow you to place anything on top of an ActiveX control. The only way I can see to actually manipulate the image would be to save the picture to file then read that bmp into a picture control. This wouldn�t be particularly fast but should be OK if you are just operating at normal webcam speeds. Another alterative would be to purchase the NI 1394 Drivers (For Firewire cameras) and use a Dcam compatible Firewire Camera.

Jon Bowers
Applciations Engineer
NIUK

[Copperwhite]

yes, I've tried that and it does work but the picture updates only about every 4-5 seconds, a bit slow but at least I have something that works.

As regards the firewire cams, I know 0 about these. But from what you say there would be no problems placing cross hairs or anything I want as an overlay on these images?

Thanks,
Rob