image-processinglabwindowscvi

Identify GREEN color in an image with NI VISION in Labwindows\CVI

I am using NI VISION imaqColorHistogram(...) in CVI which gives me a report for each plane, for a colorMode that i choose ( RGB , HSL HSV, HSI,CIE, CIEXYZ ) on an image which needs to contains a GREEN spot (the spot is most of the image)

 

A report includes:

 

int* histogram; //An array describing the number of pixels that fell into each class.
int histogramCount; //The number of elements in the histogram array.
float min; //The smallest pixel value that the function classified.
float max; //The largest pixel value that the function classified.
float start; //The smallest pixel value that fell into the first class.
float width; //The size of each class.
float mean; //The mean value of the pixels that the function classified.
float stdDev; //The standard deviation of the pixels that the function classified.
int numPixels; //The number of pixels that the function classified.

 

I want to verify that the most of colored image is as closest to GREEN. 

What ColorMode should i use? and what should be my criteria on that report?

 

Solution

  • I used HSL color mode and checked the Hue plane only.

    By observing the hue Value (in windows Paint) of several pictures, i set the tolerance of the Hue value and checked it via mean field in the report.

    Works like a charm.