How do I fix this call of GLCM on gocv

Question

Here's my code to produce a glcm using gocv, the functions of imageprocessing package aren't important to this issue, with them a read images from a folder. I'm trying to get the GLCM from the third image (Images[2]), but a get and error when running it. How can I fix it?.

package main

import (
    "./imageprocessing"
    "gocv.io/x/gocv"
    // "fmt"

)
/** CovarFlags
    // CovarScrambled indicates to scramble the results.
    CovarScrambled CovarFlags = 0

    // CovarNormal indicates to use normal covariation.
    CovarNormal CovarFlags = 1

    // CovarUseAvg indicates to use average covariation.
    CovarUseAvg CovarFlags = 2

    // CovarScale indicates to use scaled covariation.
    CovarScale CovarFlags = 4

    // CovarRows indicates to use covariation on rows.
    CovarRows CovarFlags = 8

    // CovarCols indicates to use covariation on columns.
    CovarCols CovarFlags = 16
**/

/**
 *
 * @brief      { function_description }
 * @return     { description_of_the_return_value }
 */
func main() {
    
    var size int
    
    size  = imageprocessing.FolderLength("./imageprocessing/Images/danger")

    Images := make([]gocv.Mat,size)

    GLCM := gocv.NewMat()

    mean := gocv.NewMat()

    imageprocessing.ReadFolder(Images,"./imageprocessing/Images/danger",true,false,true)

    
    //CalcCovarMatrix(samples Mat, covar *Mat, mean *Mat, flags CovarFlags, ctype MatType)
    gocv.CalcCovarMatrix(Images[2], &GLCM, &mean, gocv.CovarCols, Images[2].Type())

    window := gocv.NewWindow("Images[2]")
    window.IMShow(Images[2])
    window.WaitKey(0)

    window.IMShow(GLCM)
    window.WaitKey(0)
}

Answer 1

I was passing an RGB Image to the function, which I thought would automatically deal with this. I didn't read the function specifications properly. that's was the problem.

imageprocessing.ReadFolder(Images,"./imageprocessing/Images/danger",true,false,false)

func ReadFolder(Images []gocv.Mat, folder string, print bool, show bool, colorfull bool)