make calibration to image without using vision assistant

[abdelhady]

Hi every one

I want to make calibration to image from front panel while the program running 

I achived to enable user to draw line or draw to points on image , then the program return the distance between two points or the line lenght 

my calibration is linear and very simple

I tried to use (IMAQ set simple calibration 2.vi) but I didn't know, what I should connect to( x step & y step) terminals 

can any one tell me how to solve this proplem or give me some advises

[MoviJOHN]

If you are new to LabVIEW, I would recommend that you create a calibration script in Vision Assistant, and then use the export to LabVIEW functionality to save the steps as a VI.  Then you can have a look, and adpat it to your needs.

[muks]

Why not use vision assistant?

[abdelhady]

I build code that run in real time, so I have to build code using low level blocks

[abdelhady]

I open front panel after making calibration in vision assisstant but, I can't understand how to enter distance value between two pointsmake calibration

[muks]

X step and y step are to be determined by your image. can you post an image that you want ot be calibrated?

[Klemen]

Hello,

using simple calibration model, you realize that you disregard the lens distortion? It is also advisable that the camera is perpendicular to the inspected object. Here, a telecentric lens helps too.

The simple calibration performs direct conversion from pixels to real-world units. For example, if you know a real world object that you measure is 10 mm in size and it occupies 10 pixels on the image, then the conversion factor is 10mm/10pix = 1mm/pix.

So, you want to measure an object with size U (in pixels), you use the equation:

X = 1mm/pix * U (note that this is for horizontal direction, vertical direction is analogous)

Best regards,

K

[abdelhady]

 After I made calibration I connect image to some sequential operation image subtraction, edge deteection, threshold, basic morphlogy and advanced morphology

after that I connecte image to vision assistant that contain only particle analysis, but I found that real world parameters not active

[Klemen]

Hello,

do you apply the calibration to the image using IMAQ Set Calibration Info (prior to any analysis)?

Best regards,

K

[abdelhady]

Dear Klemen

I use (IMAQ set simple calibration then IMAQ set calibration axis info )

then image enter to some image processing function finally enter particle measurment 

particle measurment calibration valid indicate true, but real world measurment still not change