muthu's profile - activity

I want to extract a submatrix from a martix at a particular instant and add it to the main matrix while the submatrix remains constant and the main matrix changes ...

I m confused using submat() function and ROI concept...

Pls explain me about submat,ROI,colRange,rowRange and also locateROI

I wanna implement object recognition in android java using SIFT/SURF...

Can anyone pls tell meWhat is the JAVA wrapped equivalent??

I'm planning to implement user interface through color/fiducial markers in fingers in Android..

Can anyone help regarding this?

At its least level black marker on white bg is sufficient which passes its axes values to the corresponding function in Android interface class.

Pls help me about the user interface class by which i can do this...

My mistake was i didn't convert the image from default BGR to RGB..so the values had been going in the reverse order.

yes of course i did...the problem persists!

yes..they work...also i have enabled permission to install 3rd party apps in the settings

I have tried with Jellybean and Froyo..And with OCV4Android versions 2.4.3.1 & 2.4.4 ..none of them worked.. Yes the default android camera worked. Should I specify the camera resolution or the screen resolution using setResolution().

I'm developing opencv apps in android in and testing them in Beagleboard-xm and Embest DevKit8500,both having ARM Cortex-A8 processor..

In both of the boards connected camera is working normally in the android camera app. But the opencv apps donot work(not even the samples).

In Javacamera, the error message "It seems that your device does not support camera(or it is locked).Application will be closed)

In Nativecamera, the app doesnt even open.

How can i fix this problem?The camera i'm using a UVC camera with 1.3MP resolution.

i'm developing in android -java...can u pls tell the corresponding wrapping

ok thank u...It is said that SURF/SIFT returns empty objects since they're patented...Is there any way to use them??

For Freak descriptor which detector i have to use??also while matching, which matcher is supposed to be used?

Can anyone provide info. regarding what matcher is supposed to be used to brisk,brief,orb,sift,surf...

ya of course i followed...I dint get any syntactical error..there's no prob until descriptor extraction..just when i include the code foe matching the app is force closed(eclipse emulator)...

I'm trying to match an input image with image in the file("coke.jpg") in android.. The code works before matching step.(up to extracting descriptors)..Im even able to see the keypoints in drawn..But matching stops the program...

            inputFrame.copyTo(mRgba);
            File root = Environment.getExternalStorageDirectory();
            File file = new File(root, "coke.jpg");
            m1 = Highgui.imread(file.getAbsolutePath());    

            Imgproc.cvtColor(m1, m3, Imgproc.COLOR_BGRA2GRAY);

            Imgproc.cvtColor(mRgba, mIntermediateMat, Imgproc.COLOR_BGRA2GRAY, 4);

           FeatureDetector detector = FeatureDetector.create(FeatureDetector.ORB);

           detector.detect(mIntermediateMat, keypoints);
           detector.detect(m3, keypoints1);

           DescriptorExtractor extractor = DescriptorExtractor.create(DescriptorExtractor.ORB);
           extractor.compute(mIntermediateMat, keypoints, features);
           extractor.compute(m3, keypoints1, features1);

           MatOfDMatch matches1=new MatOfDMatch();

           DescriptorMatcher flannmatcher1=DescriptorMatcher.create(DescriptorMatcher.FLANNBASED);

          **flannmatcher1.match(features, features1, matches1);**

Please help me over this..Do i need to initialize MatOfDMatch in a different way??

I want to read an image from sdcard to Mat object and use it...here's the snippet

            inputFrame.copyTo(mRgba);
            Rect roi=new Rect(10, 10, 128, 128);
            Mat sm=new Mat(m2,roi);
            sm=Highgui.imread("/mnt/sdcard/coke.bmp");
            Core.addWeighted(mRgba,0.5, m2,0.5,0, mRgba);

The image i read is of size 128*128 ...so i defined a submat with the exact ROI range... I mounted the sd-card image and also included the file in it.... Yet the uotput doesnt show the imaeg... The Mat m2 is empty

I also wanna know if the image can be of larger size than the Mat to which i read??If so will it be rescaled automatically??

After obtaining the descriptors i used knnmatch() after declaring object for flann based matcher to match the test and the query features.. But in its syntax matches.knnMatch(Mat queryDescriptors,List<matofdmatch> matches,int k) ,the List<matofdmatch> ,i constructed it with new List<matofdmatch>() and it automatically added unimplemented methods....yet my app closes abrubptly... I can see in c/c++ the argument in that place is only a 2-d array...but here already use Mat and yet why do we use List??? Even if its correct why do i get this problem?? PLS HELP ME OVER THIS...I'M STRUCK HARD ON THIS PROBLEM....

Can i use this for object recognition by assessing the degree of match???Why cascadeclassifier is used for obj reconition ??why not this??

I read about cascade classifier to do object recognition from these links... http://docs.opencv.org/doc/user_guide/ug_traincascade.html http://docs.opencv.org/doc/tutorials/objdetect/cascade_classifier/cascade_classifier.html

To to do cascade classifier training the method opencv_createsamples has to be used... How can i implement thins in android - java.. I dint find this method in java documentation...

Please help me over some basic codes in java to train cascade classifier...Also if the description file format is the same??

Thanks a lot mike :)

thank u so much...again i have an issue.. when the roi starting point is near the bounday and if the height,width exceeds the boundary level,then the prog stops...how can i fix it??

So will the main matrix be altered after addition?? since we take only reference for the submatrix...right??

Hello.... I want to implement recognition of different objects in opencv android.... Pls guide me through this.. If i can use surf descriptors and match and assess the degree of matching ??or I should i use cascade classifier and ObjDetect class ..pls share me some tutorials or java code regarding this... Thank you