Simple Question: Image Display Zoom Out

[liaw82]

Hi..There goes some simple questions..

1. How to zoom out an image displayed in image display window? p.s. If you move the mouse pointer on the image, the pointer will change to a "zooming" icon. After I pressed the image will be zoomed. However there was no way for me to zoom it back to original size unless I del the image window and create another one..

2. Regarding the USB webcam driver for vision 7.1, is there any way to automatically resize the size of the image frame instead of using the propertypage vi to set it manually once the program starts? I'm currently using creative webcam live pro.. I set it by using their software and supposingly labview will follow the exact setting..but it din't..

Any idea is welcome...

thx for help..

[Ken Pietrzak]

I can answer the first one for you. Just hold down the Shift key while you press the mouse button to zoom out.

[nickbike]

liaw82,
Unfortunately, if the camera manufacturer's driver does not hold the last resolution value you set while open, LabVIEW will just read the default value. This causes you to have to set resolution everytime the VI is run using the "IMAQ USB PropertyPage.vi". Since the Property Page calls directly into the camera's driver, changing the default values would require rewriting the driver. I tried creating a VI that would programatically manipulate the property page, but to no avail since its working directly off the DLL for the camera.

Nicholas C
National Instruments
Applications Engineering

[George Lee]

Hello,

Is there a way to set the output size of the image without using the IMAQ USB propertypage.vi after about one year? Thanks!

[George Lee]

I just found that in http://forums.ni.com/ni/board/message?board.id=170&message.id=154541&view=by_threading&page=2, Brad said updating to driver 1.1.0 can program the size. I can only find driver 1.0 on NI website. Where is the link of driver 1.1.0? Thanks!

[George Lee]

Maybe I'm using the new version. Changing the value (0,1,2,....29) of video mode in USB init.vi, the size of the image can change a little, not as big scale as that in the propertypage.vi.

[T-Route]

Hi George,

Thank you for contacting National Instruments.  The USB Driver version 1.1.1 is actually the driver found at:

http://zone.ni.com/devzone/cda/epd/p/id/5030

It doesn't specifically say that it is the 1.1.1 driver but it is.  The USB Driver is not fully supported by us yet, it is mainly provided for acquisition functionality only.  The driver is set "as is" and has not been developed beyond that.  However the IMAQ USB ProperyPage VI is just calling the USB driver for your specific camera so you could maybe use a call library function node to set the image size that is brought in.  We have many examples on using call library function nodes in our example finder.  The best one to start with is: Call DLL.vi.  I hope this helps. 

Regards,
Mark T
National Instruments