gocv.NewPointVectorFromMat(img) throwing Exception

[zaargham]

While converting a gocv.Mat into point vector using NewPointVectorFromMat func panic/exception is occuring

exception: what(): OpenCV(4.6.0) /tmp/opencv/opencv-4.6.0/modules/core/src/copy.cpp:320: error: (-215:Assertion failed) channels() == CV_MAT_CN(dtype) in function 'copyTo'

Steps to Reproduce

1. load a image from dir img:=gocv.IMRead("dir",color)
2. pv := gocv.NewPointVectorFromMat(img)

Your Environment

• Operating System and version: ubuntu 20.4 focal
• OpenCV version used: 4.0 and above
• How did you install OpenCV? sudo apt instal libopencv-dev and make install for gocv
• GoCV version used: 0.30.0
• Go version: go1.18.4 linux/amd64
• Did you run the env.sh or env.cmd script before trying to go run or go build? No

[yg7001]

I encounter this too, when I call FitLine and try to convert line the *Mat to a PointVector line:=gocv.NewMat() gocv.FitLine(contour,&line,gocv.DistL2,0,0.01,0.01) l:=gocv.NewPointVectorFromMat(line) vx,vy,x1,y1:=l.At(0).X,l.At(0).Y,l.At(1).X,l.At(1).Y; // vx,vy,x1,y1:= line.GetUCharAt(1,0),line.GetUCharAt(1,1),line.GetUCharAt(1,2),line.GetUCharAt(1,3)