Re: [javacv] JavaCV errorin cvHoughCircles: error:(-5:Bad argument) Unknown array type in function 'cv::cvarrToMat'

[Samuel Audet]

That just means cvHoughCircles() doesn't support the format of your
image. You'll need to convert it to what it supports as documented here:
https://docs.opencv.org/4.1.2/dd/d1a/group__imgproc__feature.html#ga47849c3be0d0406ad3ca45db65a25d2d
That is: 8-bit, single-channel, grayscale input image.

On 4/14/20 10:18 PM, Viktoria Kübler-Tesch wrote:
> Hi ,I'm new to JavaCV and I'm trying to use this piece of software to
> detect circles in a picture.I found a blogpost online from 2013 and I've
> been trying to adjust it (this is the original source:
> http://opencvlover.blogspot.com/2012/07/hough-circle-in-javacv.html ).
> However the error (shown in the subject) keeps appearing. I'm assuming
> it is because Java, OpenCV, JavaCV,.. are all on my D:\ drive and the
> program is trying to save/acces something on my C drive and there might
> not be access ?! How do I resolve this? (Thanks in advance)
>
> I'm using Eclipse with the newest OpenJava Development Kit.
> This is the full error message:
>
> Exception in thread "main" java.lang.RuntimeException: OpenCV(4.1.2)
> C:\projects\javacpp-presets\opencv\cppbuild\windows-x86_64\opencv-4.1.2\modules\core\src\matrix_c.cpp:185:
> error: (-5:Bad argument) Unknown array type in function 'cv::cvarrToMat'
>
>     at org.bytedeco.opencv.global.opencv_imgproc.cvHoughCircles(Native Method)
>     at imageProcess.Main.main(Main.java:67)
>
>
>
> This is the Code (without the imports):
>
>
> public class Main {
>
>     public static void main(String[] args) {
>
>         //reading the image
>         Mat trial= imread("HFSBs.png");
>         IplImage trial2= new IplImage (trial);
>
>         //more problems -> not gonna convert it to gray
>         ///converting it to gray
>
>         //CvSize size= trial2.asCvMat().cvSize();
>         //IplImage gray = cvCreateImage(size, 8, 1);
>         //cvCvtColor(trial2, gray, CV_BGR2GRAY);
>
>         //auskommentiert weil vielleicht nicht benötigt+ Methode nicht aufrufbar
>         //cvSmooth(gray, gray, CV_GAUSSIAN, 3);
>
>
>         //storage for the circles?
>         CvMemStorage mem = CvMemStorage.create();
>
>
>         //Hough transformation to find the circles
>         CvSeq circles = cvHoughCircles(
>             trial2, //Input image
>             mem, //Memory Storage
>             CV_HOUGH_GRADIENT, //Detection method
>             1, //Inverse ratio
>             100, //Minimum distance between the centers of the detected circles
>             100, //Higher threshold for canny edge detector
>             100, //Threshold at the center detection stage
>             15, //min radius
>             500 //max radius
>             );
>
>
>           for(int i = 0; i < circles.total(); i++){
>               CvPoint3D32f circle = (CvPoint3D32f) new CvPoint3D32f(cvGetSeqElem(circles, i));
>               CvPoint center = cvPointFrom32f(new CvPoint2D32f(circle.x(), circle.y()));
>               int radius = Math.round(circle.z());
>               cvCircle(trial2, center, radius, CvScalar.GREEN, 6, CV_AA, 0);
>              }
>
>           //display picture
>
>
>         OpenCVFrameConverter.ToIplImage grabberConverter = new OpenCVFrameConverter.ToIplImage();
>         Java2DFrameConverter paintConverter = new Java2DFrameConverter();
>         Frame frame = grabberConverter.convert(trial2);
>         BufferedImage trial3=  paintConverter.getBufferedImage(frame,1);
>
>           CanvasFrame displayFrame= new CanvasFrame("Result");
>           displayFrame.showImage(trial3);
>
>           //cvShowImage("Result",trial2);
>           KeyEvent key;
>         try {
>             key = displayFrame.waitKey(0);
>         } catch (InterruptedException e) {
>             System.out.print(e.getMessage());
>             e.printStackTrace();
>         }
>
>
> }
> }
>

[shira Jacobs]

How to convert the image?

ב-יום רביעי, 15 באפריל 2020 בשעה 03:52:56 UTC+3, Samuel Audet כתב/ה: