Live Image Display Scaling

[The_Happy_Coder]

Hello,

Anyone had any experience with controlling the image scaling function for a live feed? 

Essentially, I’m grabbing an image using the Vision Acquisition Express block.  I have a 12-Bit GigE camera and I would like to threshold the display so that, say, I optimise the image for values between 0-600.  To do this I am setting the 16-bit mapping display properties prior to starting my VI.

When I configure the block to load a stored jpeg I have already captured (see top image & code) then I can control the threshold as I’d expect.  However, when I do the same thing for the live feed I get no effect…

I output the 16-bit mapping display properties to verify that I had set both images the same.

I don’t have much experience of Labview & Vision, so hopefully it is just a simple mistake somewhere…

Your time & effort is much appreciated,

Regards,

Chris

Ps. Things that might help: I’m using LabVIEW 8.6

For the live feed, I was using the settings: Continuous Acquisition with Inline processing / Acquire Most Recent Image, although I tried others too.

[Andrey_Dmitriev · Accepted solution]

Is is well known bug (or "feature"). IMAQ Dsiplay can be scaled only if your image 16 bit and bith depth unscpecified. Inside of IMAQ Acquisition SubVIs Bit Depth was set according to camera settings (12 bit in your case) and this prevent scaling.

Try to set bit depth to 0 before display with IMAQ Image Bit Depth

Andrey.

[The_Happy_Coder]

Thankyou Andrey... that has made my weekend start that little bit better! 🙂

One of my old cameras is 8-bit.  I have only been using it so that I can have 2 sources to work with simultaneously, but given what you have said (and my very recent testing) it appears I cannot scale the image in the same way.  Do you know if there is a solution to this?  Ideally I would just convert the output images to I16, but I don't believe it works as easy as that. 😞

All thoughts welcome... thankyou again.

[tylerw]

In VDM 2010 the image display control now has more options for 16 bit display mapping. There is now a checkbox for "Apply mapping only when configured Bit Depth is 0". Leave this unchecked and you should be able to always obey your settings even when aquisition sets the bit depth on your image.