I want to work on Opencv3 with Go-Lang. I have followed step according to http://gocv.io I have installed it successfully but now I am getting an error "eigenNonSymmetric is not a member of 'cv' " at core.cpp:344:9 any help. And I am on Ubuntu 18.04

Description

I am getting this error

gocv.io/x/gocv

core.cpp: In function ‘void Mat_EigenNonSymmetric(Mat, Mat, Mat)’: core.cpp:345:9: error: ‘eigenNonSymmetric’ is not a member of ‘cv’ cv::eigenNonSymmetric(*src, *eigenvalues, *eigenvectors); ^~~~~~~~~~~~~~~~~

Your Environment

• Operating System and version: Ubuntu 18.04
• OpenCV version used: 3.4.1
• How did you install OpenCV? according to gocv.io
• GoCV version used: latest
• Go version: 1.10.2
• Did you run the env.sh or env.cmd script before trying to go run or go build? no

When reviewing #135, I was like "wait, why is this test actually passing?". The test was about flipping a Mat into a brand new Mat, both passed to a function that looks roughly like this:

func Flip(src Mat, dst Mat, flipCode int) {}

In Go, parameters passed by value (default like above) should not be modified (and in any case, it will never change the value in the parent block). In gocv, this would works though because we manipulate a C pointer under the hood but this is a bit misleading.

Question is: could we agree on a "convention" stating that all arguments modified should be passed by pointer?

If we take the Flip() function as an example:

src := ...
dst := gocv.NewMat()

// wait, how does `dst` can be updated? No return-value either? Hmmm.
gocv.Flip(src, dst, 0);

// versus

// oh right so `Flip` takes a `src` Mat and puts the result in `dst`. Lovely <3
gocv.Flip(src, &dst, 0);

Hello, I cannot run my test application under Visual Studio Code. I have the following error: file not found: opencv2/opencv.hpp Any idea? Regards Fooky

Hi! I am getting

imgproc.cpp:61:28: error: expected '(' for function-style cast or type construction

error, tried running simple Hello World! sample.

Description

I want to use Openvino and i have installed it on windows 10. Only one peoblem is I am getting error something like this.

• Did you run the env.sh or env.cmd script before trying to go run or go build?

there is no file at

source /opt/intel/computer_vision_sdk/bin/setupvars.sh

and i tried to find it out but it was for ubuntu and i ran it it's not working.

so can you help me out here. where can i get

setupvars.sh for window 10

Your Environment

• Operating System and version:Windows 10
• OpenCV version used:3.4.1
• How did you install OpenCV? according to gocv.io
• GoCV version used: latest
• Go version: 10.1.2

gocv.NewMat ToImage function memory leak

Description

func (od *OpenCVDecoder) ReadJpeg() ([]byte, error) {
	img := gocv.NewMat()
	defer func() {
		err := img.Close()
		fmt.Println("ReadJpeg err :",err)
		//runtime.GC()
		//fmt.Println("read gc")
	}()
	if ok := od.vc.Read(&img); !ok {
		return nil, nil
	}

	if img.Empty() {
		return nil, nil
	}
	_, err := img.ToImage()
	if err != nil {
		return nil, err
	}
	//i, err := ImageToJpeg(iimg)
	return nil,nil
}

iimg variable not release.i must use runtime.GC(),but it didn't work well also.i think img.Close() dosen't work.

after task stop. pprof report

(pprof) top
Showing nodes accounting for 13.85MB, 100% of 13.85MB total
      flat  flat%   sum%        cum   cum%
    7.91MB 57.13% 57.13%     7.91MB 57.13%  image.NewRGBA
    5.94MB 42.87%   100%     5.94MB 42.87%  gocv.io/x/gocv._Cfunc_GoBytes

(pprof) list ToImage
Total: 13.85MB
ROUTINE ======================== gocv.io/x/gocv.(*Mat).ToImage in /Users/x/go/pkg/mod/gocv.io/x/[email protected]/core.go
         0    13.85MB (flat, cum)   100% of Total
         .          .    753:   }
         .          .    754:
         .          .    755:   width := m.Cols()
         .          .    756:   height := m.Rows()
         .          .    757:   step := m.Step()
         .     5.94MB    758:   data := m.ToBytes()
         .          .    759:   channels := m.Channels()
         .          .    760:
         .          .    761:   if t == MatTypeCV8UC1 {
         .          .    762:           img := image.NewGray(image.Rect(0, 0, width, height))
         .          .    763:           c := color.Gray{Y: uint8(0)}
         .          .    764:
         .          .    765:           for y := 0; y < height; y++ {
         .          .    766:                   for x := 0; x < width; x++ {
         .          .    767:                           c.Y = uint8(data[y*step+x])
         .          .    768:                           img.SetGray(x, y, c)
         .          .    769:                   }
         .          .    770:           }
         .          .    771:
         .          .    772:           return img, nil
         .          .    773:   }
         .          .    774:
         .     7.91MB    775:   img := image.NewRGBA(image.Rect(0, 0, width, height))
         .          .    776:   c := color.RGBA{
         .          .    777:           R: uint8(0),
         .          .    778:           G: uint8(0),
         .          .    779:           B: uint8(0),
         .          .    780:           A: uint8(255),

Steps to Reproduce

Your Environment

• Operating System and version: macOS
• OpenCV version used: 4.5.0
• How did you install OpenCV? brew install
• GoCV version used: 0.25.0
• Go version: 1.15.x
• Did you run the env.sh or env.cmd script before trying to go run or go build? no

an attempt to wrap the tracking module from opencv_contrib

W I P , rfc.

this is making heavy use of c++ / go interfaces.

Tracker_Init() and Tracker_Update() only need to be implemented once (in c++), and can be reused for any go implentation of the Tracker interface, saving a ton of boilerplate code

if we'd use interfaces more often, properly, e.g, there'd be no need to do this again and again , and also have all this boilerplate repetition here and here and so on ..

@willdurand , may i challenge you / pick your mind on this idea, too ?

(it still needs a wrapper function on the go side, with the correct implementation type as self, to satisfy the go interface, but all we need to do there is to extract the C.Tracker from the go type, and pass it on to the shared c++ wrapper)

also tests can be rigorously simplified, if all we need to do is pass a different implementation instance to the same base test

some things did not make it:

• GOTURN: needs a XXXmb pre-trained dnn, can't be tested without (throws exception) * CSRT: only available in 3.4.1 .. i'll just add it
• MultiTracker: i've made an attempt, but there are problems. i'll leave the code in comments (for now), maybe someone has an idea. a: i see no proper way to add new tracker instances to it. the way i tried, worked on my win box, but throws an exception on travis. it's also somewhat unclear, how & when to Close() the added trackers b: i'm unable to release a C.struct_RECTS in cgo, (can't access Rects_Close somehow) c: gocv.toRectangles(ret) would be very useful here, but it's private in gocv all in all, opencv's MultiTracker is just a shallow wrapper around vector<Ptr<Tracker>>, maybe we're better off, building a mock class in pure go ?

brew install hybridgroup/tools/opencv

Description

brew install hybridgroup/tools/opencv

url: (56) LibreSSL SSL_read: SSL_ERROR_SYSCALL, errno 54 Error: Failed to download resource "opencv" Download failed: https://github.com/hybridgroup/homebrew-tools/releases/download/v0.10.1/opencv-4.0.0.high_sierra.bottle.tar.gz Warning: Bottle installation failed: building from source. ==> Downloading https://github.com/opencv/opencv/archive/4.0.0.tar.gz ==> Downloading from https://codeload.github.com/opencv/opencv/tar.gz/4.0.0

curl: (22) The requested URL returned error: 404 Not Found

Steps to Reproduce

Your Environment

• Operating System and version:
• OpenCV version used:
• How did you install OpenCV?
• GoCV version used:
• Go version:
• Did you run the env.sh or env.cmd script before trying to go run or go build?

Hello there. I have one really strange problem with SIFT detector. I use it in our service and seems like there is memory leak. I use method DetectAndCompute. When I looked at code I found that defer KeyPoints_Close is commented. I was able to make new test binding KeyPoints_Close2 and free memory, but it didn't solve my problem. I have no clue how to reproduce it without using service. I mean simple application doesn't cause such big memory consumption.

For example here is some code:

func TestSift(t *testing.T) {
	gray := gocv.IMRead("path_to_image", gocv.IMReadGrayScale)

	sift := contrib.NewSIFT()
	defer sift.Close()

	res := make([]point, 0) //this is used as result in service's code.
	for iter := 0; iter < 50; iter++ {
		mask := gocv.NewMat()
		defer mask.Close()
		k, d := sift.DetectAndCompute(gray, mask)
		defer d.Close()

		for i, v := range k {
			var tmp []float64
			for j := 0; j < d.Cols(); j++ {
				tmp = append(tmp, float64(d.GetFloatAt(i, j)))
			}
			res = append(res, point{keypoint: v, descriptor: tmp})
		}
	}
	utils.ShowImage(gray) //This function just shows image in new window. 
}

Similar code is used in my service and I have crashes (because of memory problem). Interesting thing - using BRISK (for example) fixes this problem, but using SURF - not.

I wasn't able to find significant difference between BRISK and SIFT bindings, so maybe there is another problem. I have C++ application and it hasn't such problem, so maybe there is some golang specific things.

I tried to use pprof, but without any luck (But maybe I didn't use it in right way). Valgrind also shows that there is no memory issues.

I just have no clue what's happening there. Top shows, that memory usage increases by ~300Mb after each call. Does anybody face this problem?

Description

1. I followed the readme to install opencv.
2. when I finished the install step ... I got this issue...

Does anyone know what is it means?

# gocv.io/x/gocv
dnn.cpp: In function 'cv::Mat* Net_BlobFromImage(Mat, double, Size, Scalar, bool, bool)':
dnn.cpp:119:102: warning: passing NULL to non-pointer argument 1 of 'cv::Scalar_<_Tp>::Scalar_(_Tp) [with _Tp = double]' [-Wconversion-null]
         return new cv::Mat(cv::dnn::blobFromImage(*image, scalefactor, sz, NULL, swapRB, crop, ddepth));

and then, when I run the gocv, this issue always has happened.

Your Environment

PRETTY_NAME="Debian GNU/Linux 10 (buster)"
NAME="Debian GNU/Linux"
VERSION_ID="10"
VERSION="10 (buster)"
VERSION_CODENAME=buster
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"

• Operating System and version: debian
• OpenCV version used: opencv lib version: 4.2.0
• How did you install OpenCV? use makefile
• GoCV version used: gocv version: 0.22.0
• Go version: go version go1.13.1 linux/amd64
• Did you run the env.sh or env.cmd script before trying to go run or go build? No

Description

The current NewMatFromBytes (in gocv 0.15) does not copy the data from the slice but instead uses an unsafe pointer to the data when initializing the OpenCV Mat. Furthermore, the gocv Mat maintains no reference or anything to this data to prevent that slice from being garbage collected (the relationship between the Mat and the byte slice may not even be picked up by the escape analysis -- perhaps the byte slices are being allocated on the stack!).

I don't know if this was expected behavior or not, but I was caught off guard! If this is working as designed, kindly leave a few notes in the documentation for NewMatFromBytes.

My workaround for now is to clone the Mat after calling NewMatFromBytes (before the []byte goes out of scope).

Steps to Reproduce

Here is a test case that reproduces the strange problems I was experiencing (Mat's getting overridden after the byte slice is out of scope).

import (
	"crypto/rand"
	"testing"

	"github.com/stretchr/testify/require"
	"gocv.io/x/gocv"
)

// Equal returns whether the images are equal.
func Equal(img1, img2 gocv.Mat) bool {
	eqMat := gocv.NewMat()
	gocv.Compare(img1, img2, &eqMat, gocv.CompareNE)
	count := gocv.CountNonZero(eqMat)
	eqMat.Close()
	return count == 0
}

func TestMatFromBytes(t *testing.T) {
	size := 500
	var img, imgCloned gocv.Mat
	var err error

	makeImg := func() {
		b := make([]byte, size*size)
		_, err = rand.Read(b)
		img, err = gocv.NewMatFromBytes(size, size, gocv.MatTypeCV8U, b)
		require.NoError(t, err)
		imgCloned = img.Clone()
	}

	useMemory := func() {
		b := make([]byte, size*size)
		_, err = rand.Read(b)
	}

	makeImg()

	// This assertion will pass.
	require.True(t, Equal(img, imgCloned))
	for i := 0; i < 100; i++ {
		useMemory()
	}

	// This assertion will fail!
	require.True(t, Equal(img, imgCloned))
}

Your Environment

• Operating System and version: Mac OSX 10.13.6
• OpenCV version used: 3.4.2
• How did you install OpenCV? (homebrew)
• GoCV version used: 0.15.0
• Go version: 1.10.3
• Did you run the env.sh or env.cmd script before trying to go run or go build? (N/A?)

P.S. OpenCV in go is awesome and I look forward to this project becoming mature! Thanks for all the work you guys do!

docker image from dockerhub

I see docker image from https://hub.docker.com/r/gocv/opencv/tags. I intended to use image 4.7.0-gpu-cuda-11.2.2 to cross build my onnx image detection problem used in windows.

sudo docker run --gpus all -it  -v /home/xxx/Document/apex:/data gocv/opencv:4.7.0-gpu-cuda-11.2.2
docker: Error response from daemon: failed to create shim task: OCI runtime create failed: runc create failed: unable to start container process: exec: "go version": executable file not found in $PATH: unknown.
ERRO[0000] error waiting for container: context canceled

But here comes the problem, the golang path in the image is no properly configured.

exec: "go version": executable file not found in $PATH: unknown.

I hope there may be some docs.

opencv/aruco.hpp is still part of opencv_contrib in OpenCV 4.7.0. (related to #1045)

We only use core functions and don't have opencv_contrib as part of our build process. When attempting to update to gocv 0.32.1/OpenCV 4.7.0 we encountered the error: aruco.h:6:10: fatal error: opencv2/aruco.hpp: No such file or directory. Including only opencv2/opencv.hpp appears sufficient.

Though we don't use the aruco, make test passes with this change.

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

I want to get the camera content via VideoCaptureDevice and when I pass in my virtual camera ID, it always turns on the virtual camera on the first run and the computer camera on the second run.

Description

my code: func main() { webcam, _ := gocv.VideoCaptureDevice(1) // my virtual camera id is 1 defer webcam.Close() window := gocv.NewWindow("test") defer window.Close() img := gocv.NewMat() defer img.Close() timeUnix:=time.Now().Unix() + 3 for { if time.Now().Unix() > timeUnix { break } webcam.Read(&img) window.IMShow(img) window.WaitKey(1) } }

Before executing the programmy camera id

After executing the program. The camera id changes. Procedure

Your Environment

• Operating System and version: MacOS Ventura 13.0.1 macbookpro M1
• OpenCV version used: 4.5.3
• How did you install OpenCV? yes
• GoCV version used:0.31.0
• Go version: go1.17.2 darwin/arm64
• Did you run the env.sh or env.cmd script before trying to go run or go build? no

Description

I am trying to detect blurry images according to this Python example

func main() {
	img := gocv.IMRead("dog.webp", gocv.IMReadColor)
	defer img.Close()

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

	gocv.CvtColor(img, &gray, gocv.ColorBGRToGray)

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

	gocv.Laplacian(gray, &blur, gocv.MatTypeCV64F, 1, 1, 0, gocv.BorderDefault)

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

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

	gocv.MeanStdDev(blur, &meanStdDev, &stdDev)
}

How can I get variance out of meanStdDev or stdDev? I know this code is pretty much ugly. :D

Your Environment

• Operating System and version: Linux Mint 20.3 Una
• OpenCV version used: 4.6.0
• How did you install OpenCV? By instructions from this repository.
• GoCV version used: 0.31.0
• Go version: 1.19.3
• Did you run the env.sh or env.cmd script before trying to go run or go build? No, my build works.

Is it possible to integrate PaddleOCR into this project ? It is probably the best general purpose OCR so far. I am sure it will help a lot, though I found this job is beyond my reach .