"Auto Range" white level (MAX) on labview.

[Alberto_Enciso]

Hi

I'm doing an equipment to test thousands of video sources. Between different video sources there are differences that i want to eliminate.

Doing tests, changing the white level of the acquisition, the problem seems to be solved. This has been done on MAX doing click on the "auto range" white level button of the "acquisition parameters" tab of the frame grabber configuration.

But now i want to do that on the frame grabber.

Using property nodes, i can set the white level voltaje.

Questions are:

1) Is it possible to automatically calculate the white level adjust on labview as MAX does? I mean a VI already done that can do it.

2) If its not possible, can someone know the correct steps to adjust this voltaje?

My idea is to read a white portion of the image. If the RGB values are not close to 250 for each R,G and B, then i can change the white level voltaje, then read an image again. Until i get an acceptable value. But i think there is a better way to do it.

Thanks in advance.

[muks]

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If the RGB values are not close to 250 for each R,G and B, then i can change the white level voltaje, then read an image again. Until i get an acceptable value. But i think there is a better way to do it.

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If i understand it correctly. You can continously grab the images by using the grab/acquire inside the while loop. Apply the gamma correction (RGB) in the acquired image. When you are satisfied exit the loop and save it/process it.

[Rialter]

HI Alberto;

I haven't been able to find a function that does the leve dajust for color images automatically, but you can use the  IMAQ Color BCGLookup found in the Vision and Motion >> Image Processing >> Color Processing palette. The function corrects the image (luninance, contrast and gamma) depending on the parameters you input, but I have done some tests with the default ones and the images obtained have a better distribution, so if you use that function you should not need to be changing the parameters dinamically and coul obtain some images more suitable for your application.

I hope the information is useful.

Good luck

[Alberto_Enciso]

Thanks for the help.

I added the IMAQ Color BCGLookup VI as an option to process some of the images i grab. I did some tests and works good.

I need to learn how to calculate the relation between the RGB values and luminance, contrast.

Best regards