blank frame

[mcholewi]

Hello,

I was tryping to develop program for Smart Camera NI 1774, using a part of program Grab (177x Smart....) and adding after retrieving an image operations like IMAQ Threshold, IMAQ Centroid and adding the Coordinate System to image (see attachment). Program suppose to find dark object on the white screen and give information about actual position.

The problem is that after IMAQ Threshold and so on, indicators Show Image are blank. Sometimes an image appears in one indicator for a fraction of a second and after is still blank. Removing IMAQ Threshold and other helps and the image is normal (but it is not my goal 🙂 ).

I don`t know what I am doing wrong. I`m pretty sure it is a little thing, obvious for anyone, but I don`t really know what it is.

The FPS indictaor works ok, and the part od Threshold and Centroid works ok (I think because values are changing, but I don`t see anything) 🙂 

[toto69 · Accepted solution]

Hi,

What are you calling a blank image? Is it a black image? If so, just check your image control is in binary display mode. You will then have red and black images.

I guess this is the problem, but I couldn't open your VI as I'm using LV 2010.

In fact, when you threshold an image, you just have 0 and 1 value pixels, and you cannot see this dynamic with your eyes. That's why binary mapping exist, to have a better dynamic and contrast.

Hope this helps

Regards

[mcholewi]

Thank you for response. You had a right, the solution was to change palete to binary. What is more I had problem with both images controls - they showed the same image. I tried to use copy image block, but it caused blinking image. I used function IMAQdx Get Image to get image with other name and it was the solution. Well, habits from matlab 🙂 

Now everything works perfect!

Thank you!