baharsan's profile - activity

I use core.inrange to skin detection but the problem is when app running about 1 minutes, it will turn off without returning any error. is this bug in opencv android ?

this my code :

       case ImageManipulationsActivity.VIEW_MODE_SKIN:
        capture.retrieve(mRgba, Highgui.CV_CAP_ANDROID_COLOR_FRAME_RGBA);
        Mat HSV = new Mat();
        Imgproc.cvtColor(mRgba, HSV, Imgproc.COLOR_RGB2HSV, 3);
        Core.inRange(HSV,  new Scalar(0, 100, 30), new Scalar(5, 255, 255), mRgba);
        Imgproc.cvtColor(mRgba, mRgba, Imgproc.COLOR_GRAY2BGRA, 4); 
        break;
    }
    Bitmap bmp = Bitmap.createBitmap(mRgba.cols(), mRgba.rows(), Bitmap.Config.ARGB_8888);
    if (Utils.matToBitmap(mRgba, bmp))
        return bmp;
    bmp.recycle();
    return null;

if i remove core.inrange, the app just running smoothly. i accept any suggestion about this, thanks.

I'am trying to use drawLargestContour mehthod to my program, but unfortunately my program suddenly turns off after about 1 minutes. I don't know why ? please some body help me :

this is my code (i use this for online capture) :

Mat HSV = new Mat();
    Imgproc.cvtColor(image, HSV, Imgproc.COLOR_RGB2HSV, 3);

    Mat mHSVThreshed = new Mat();
    //skin color detection
    Core.inRange(HSV,  new Scalar(0, 58, 89), new Scalar(25, 173, 229), mHSVThreshed);

    Mat hierarchy = new Mat(mHSVThreshed.rows(), mHSVThreshed.cols(), CvType.CV_8UC1, new Scalar(0));
    List<Mat> contours =new ArrayList<Mat>(100);

    Imgproc.findContours(mHSVThreshed, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_NONE);

    Mat Mask = new Mat();
    Mask = Mat.zeros(mHSVThreshed.rows(), mHSVThreshed.cols(), CvType.CV_8UC1);

    Imgproc.drawContours(Mask, contours, -1, new Scalar(255), Core.FILLED);

    Mat crop = new Mat(image.rows(), image.cols(), CvType.CV_8UC3);

    crop.setTo(new Scalar(0,255,0));

    image.copyTo(crop, Mask);

    Core.normalize(Mask.clone(), Mask, 0.0, 255.0, Core.NORM_MINMAX, CvType.CV_8UC1);

    Mat Biner = new Mat();
    Mask.convertTo(Biner, CvType.CV_8U);

    Imgproc.cvtColor(Biner, image, Imgproc.COLOR_GRAY2RGB, 0);
    Imgproc.cvtColor(image, image, Imgproc.COLOR_RGB2RGBA, 0);

    return image;

you can look at this answer :

Link

After some research and experiment, finally i find the light, here it is. you just need to get the image back to the default type. like this :

for (Rect r : faces){
        Core.rectangle(mRgba, r.tl(), r.br(), new Scalar(0, 255, 0, 255), 3);
        Mat roi = new Mat();
        roi = mRgba.submat(r);

        Mat gray = new Mat();
        Imgproc.cvtColor(roi, gray, Imgproc.COLOR_RGB2GRAY,1);

        Mat gray_f = new Mat();
        gray.convertTo(gray_f, CvType.CV_32F, 1.0/255, 0);

        Mat final = new Mat();
        gray_f.convertTo(final, CvType.CV_8U, 255, 0);

        Imgproc.cvtColor(final, roi, Imgproc.COLOR_GRAY2RGB,0);
        Imgproc.cvtColor(roi, roi, Imgproc.COLOR_RGB2RGBA,0);
        Mat kotak = new Mat();
        kotak = mRgba.colRange(r.x, r.x+r.width).rowRange(r.y, r.y+r.height);
        roi.copyTo(kotak);
    }     }

This is the Queen of This Answer :

        Mat final = new Mat();
        gray_f.convertTo(final, CvType.CV_8U, 255, 0);

i already use COLOR_RGB2GRAY and it run smoothly , i can deal with that, what i am still confusing is when i was trying to convert gray image to different mat of type, in this case CV_32F, then display it in android screen, it will no result, but NOT forceclose. I still cannot Convert. may be you can help me buddy.

@Niharika A : you can grab it here : http://www.mediafire.com/?2e8n8evm820peri

i want to make a simple hand detection using OpenCV Android (haar classifier, viola jones) which can running in my android device. somebody can help me tutorial? i am newbie in opencv. please support me to finish this project. thanks for your attention. thanks in advances

Best Regards baharsan

thanks, it help me a lot, i have found sample android application to detect hand using haar classification

many thanks dude, it help me a lot.

Hey There, please help me to figure it out : I have a opencv C++ code like :

 cv::Mat kernel(ks,ks, CV_32F);
    for (int y=-hks; y<=hks; y++)
    {
        for (int x=-hks; x<=hks; x++)
        {
            x_theta = x*del*cos(theta)+y*del*sin(theta);
            y_theta = -x*del*sin(theta)+y*del*cos(theta);
            kernel.at<float>(hks+y,hks+x) = (float)exp(-0.5*(pow(x_theta,2)+pow(y_theta,2))/pow(sigma,2))* cos(2*CV_PI*x_theta/lmbd + psi);
        }
    }

I want to convert below code to android

kernel.at<float>(hks+y,hks+x) = (float)exp(-0.5*(pow(x_theta,2)+pow(y_theta,2))/pow(sigma,2))* cos(2*CV_PI*x_theta/lmbd + psi);

can you help me please, thanks in advance :)

please check my edited code above, i hope you can help me out from this. i just wanna know why these code run smoothly in opencv c++ and can't run in opencv4android. thank you steven for quick answer. and how to implement rightly convertTo in android.

I Think this simple function code should help you much :

private void ExportMatToBitmap(Mat img_mat, String name) {
    Bitmap bmp = Bitmap.createBitmap(img_mat.cols(), img_mat.rows(),
            Bitmap.Config.ARGB_8888);
    Utils.matToBitmap(img_mat, bmp);
    try {
        FileOutputStream out = new FileOutputStream(name);
        bmp.compress(Bitmap.CompressFormat.JPEG, 90, out);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

Hei, I have a little problem when i try to convert opencv c++ to opencv4android. here it is :

Android Source Code -- Online Processing

    for (Rect r : faces){
            Core.rectangle(mRgba, r.tl(), r.br(), new Scalar(0, 255, 0, 255), 3);
            Mat roi = new Mat();
            roi = mRgba.submat(r);

            Mat gray = new Mat();
            Imgproc.cvtColor(roi, gray, Imgproc.COLOR_BGR2GRAY,1);

            Mat gray_f = new Mat();
            gray.convertTo(gray_f, CvType.CV_32F, 1.0/255, 0);

            Imgproc.cvtColor(gray_f, roi, Imgproc.COLOR_GRAY2BGR,0);
            Imgproc.cvtColor(roi, roi, Imgproc.COLOR_BGR2BGRA,0);
            Mat kotak = new Mat();
            kotak = mRgba.colRange(r.x, r.x+r.width).rowRange(r.y, r.y+r.height);
            roi.copyTo(kotak);
        }

C++ Source Code -- Offline Processing

 cv::Mat image = cv::imread("hand.jpg",1);
 cv::imshow("Src", image);
 cv::cvtColor(image, src, CV_BGR2GRAY);
 src.convertTo(src_f, CV_32F, 1.0/255, 0);
 cv::imshow("src", src);
 cv::imshow("src_f", src_f);

This the result of C++ :

This the result of Android :

I Think that's above code have the same result, but when i run above code in pc and in andrioid, they haven't same result. i don't know way, any body help me please to explain it. Thanks in Advance... your little help should make my life better.. :)

UPDATED

After some hard of research, i was find my final problem, i think i wrong to display Mat image, just look at this : http://stackoverflow.com/a/9471411/1593269, if i want to convert BGR to Gray image and then display it on the android screen i need this :

    Imgproc.cvtColor(image, dst4, Imgproc.COLOR_BGR2GRAY); //Convert BGR to GRAY
    Imgproc.cvtColor(dst4, image, Imgproc.COLOR_GRAY2BGR); **//Confuse with This**
    Imgproc.cvtColor(image, image, Imgproc.COLOR_BGR2BGRA); //To compate with default android standard (4 channel), so we need to change from 1 channel to 4 channel before we display

Somebody please help me to understand what the mean :

Imgproc.cvtColor(dst4, image, Imgproc.COLOR_GRAY2BGR); **//Confuse with This**

and For what this row of code ? if i don't write that's code, it will always force close. Once again, I am trying to convert mat of gray image to CV_32F, then i want to display it on the screen, and i am trying to figure it out by this :

Imgproc.cvtColor(imgmat, src, Imgproc.COLOR_RGB2GRAY,0);
src.convertTo(src_f, src_f.type(), 1.0/255, 0);
Imgproc.cvtColor(dest_mag, imgmat, Imgproc.COLOR_GRAY2RGB, 0);          
Imgproc.cvtColor(imgmat, imgmat, Imgproc.COLOR_RGB2RGBA, 0);

it will run smoothly on the screen but without desired result.(desired result : gray image with CV_32F (java primitive array))

Please Help me, i look arround over the internet and i cannot find how to implement cvSet2D in android, i use that function to gabor filtering, btw, anyone could help me how to implement gabor in android using OpenCV 2.3.1 for Android.

thanks alot

Finally it's done, thank you so much all member here and stackoverflow forum. this reference to get it done :

http://stackoverflow.com/questions/9443377/android-color-detection-using-opencv-how-to