Memory leak in ORB detector

[danhab99]

Description

I have a plain and simple implementation of ORB I got using a tutorial. When I try running this function 1000 times I see huge memory usage and it doesn't go down. I'm confident I closed all the gocv resources, I'm not passing mats between goroutines, it's just a pure function.

Steps to Reproduce

import (
	"image"
	"image/draw"

	"gocv.io/x/gocv"
)

func convertToGray(img image.Image) (*image.Gray, error) {
	bounds := img.Bounds()
	gray := image.NewGray(bounds)

	draw.Draw(gray, bounds, img, bounds.Min, draw.Src)

	return gray, nil
}

func Process(img image.Image) (result ProcessResults, err error) {
	gray, err := convertToGray(img)
	if err != nil {
		panic(err)
	}

	mat, err := gocv.ImageGrayToMatGray(gray)
	if err != nil {
		panic(err)
	}
	defer mat.Close()

	orb := gocv.NewORB()
	defer orb.Close()

	mask := gocv.NewMat()
	defer mask.Close()

	keypoints, description := orb.DetectAndCompute(mat, mask)
	defer description.Close()

	result.Description = description.ToBytes()
	result.DescCols = description.Cols()
	result.DescRows = description.Rows()
	result.DescType = description.Type()

	result.Keypoints = keypoints

	return
}

Your Environment

• Operating System and version: 5.15.143-1-MANJARO
• OpenCV version used: the one installed here
• How did you install OpenCV? go get gocv.io/x/gocv v0.35.0
• GoCV version used: 0.35.0
• Go version: 1.19
• Did you run the env.sh or env.cmd script before trying to go run or go build? Hope the docker image did