agile's profile - activity

I developed a face recognition application which is working on Samsung Galaxy S2 but it shows black screen on Motorola device, when the camera is activated. I did some research, and I found that Motorola devices use some other container for camera. Anyone has experience such issue? Any idea how to solve this problem. BTW I am using OpenCV for Android SDK 2.4.5.

I solved the problem by using the getCVmat of model to extract the Matrix at specific location and then .toString() of CVmat to extract the content of matrix as string. I save the string into database. For Matching, I retrieve the String, converted the string into float array by splitting the string and casting it to float. The values are then putted into new Matrix using Mat.put(0,0,float[]).

I solved the problem by Converting Mat to Bitmap and then Bitmap to IplImage. There is a mehtod available in OpenCV for Android for coverting Mat to Bitmap and in JavaCV for converting Bitmap to IplImage.

I am converting Mat into iplImage in Java. I found a solution in C. It uses cvSetReal2d to populate IplImage from Mat. I read about the function but i have some confusions. What is meant by "The first zero-based component of the element index" , The second zero-based component of the element index"?

@elmiguelao: Can you provide the java equivalent of this code?

How can I convert Mat image to IplImage using Opencv4 android / javacv. I am using opencv for face detection but I need javacv for face recognition. and the face recognizer class require CvArr/IplImage as an input for the train method.

yes, I am trying to split the string into string array and converting each sub string into double. After I can use the Mat.put(0,0, double) for filling the matrix. and that could be the possible solution.

I want to send the string to another application and save it in database. The application can only accept it as a string. Now I can convert it to a string by first using the getCVmat of model to extract the Matrix at specific location and then .toString() of CVmat to extract the content of matrix as string. But now I want to convert this string to OpenCV4android Mat type.

I am doing face recognition using opencv4android and JavaCV.

I did the face detection in OpenCV and created the LBP histogram through JavaCV Face Recognizer class. Now I want to save this histogram in a database.

The histogram itself is in the Matvector type, considering I am saving the model into an xml file using the model.save() method. Then I parse the xml and take the histogram into string.

I want to use opencv4android method compareHist(Mat,Mat,int) for comparison so I need to convert this string back to Mat.

How can i do it using OpenCV4andorid?

Hi how can I use the Face recognizer in OpenCV android SDK. I want to do face recognition in Android using OpenCV Android SDK.

I am using OpenCV Android SDK. I don't see the mentioned folders.

Thanks. I am doing it for android and using JavaCV. But I don't know if it source is available in JavaCV. But I can write my own predict method. i just need comareHist which is available in android opencv and javacv as well.

if confidence is the distance between test and the closest it means it is the distance return by CompareHist. i.e "dist" in the code: double dist = compareHist(_histograms[sampleIdx], query, HISTCMP_CHISQR);

If that is the case, then why the dist is compared with minDist (which is confidence value). if((dist < minDist) && (dist < _threshold)) {..}

What is the difference between "confidence" value in Face Recognizer predict method and "threshold" in model consrtuctor?

I want to just grab the LBP histogram from the source image and compare it with the previous stored LBP Histograms and I want a probabilistic match. Like top three matches. I am presently grabbing the LBP Histogram through train method and I want a set of distances from the predict method not just a single predicted label.

Thanks

I am doing face recognition in android using JAVACV and OpenCV SDK for android. I used the sample code of face detection that comes with OpenCV android SDK. Now I want to move to face recognition. I want to compute the LBP Histogram of the detected face and store it in the database which will be later matched using Chi-square with other histogram. The Face recognizer class in OpenCV has train and predict method which are not publicly exposed. Does the train method compute the Histogram of the image? How can I compute the LBP Histogram using the face recognizer class?