2020-09-21 08:13:06 -0600 | received badge | ● Popular Question (source) |
2014-07-15 05:11:45 -0600 | asked a question | Will callbacks be called once OpenCV Package Manager finish installing in Google Play Store [Android]?? Given a scenario as such: Referring to the workflow outlined in the document, Manager Workflow and the given callbacks, Loader Callback Inteface and Install Callback Interface.
Will OpenCV callbacks be called to indicate the package has been finish installing so that the activity that the user was in before being directed to Google Play Store can be resumed? |
2014-06-24 06:47:16 -0600 | commented question | How to improve grayscale image quality for eye detection? Thx for the suggestion. Just browsed through the implementation of fladmark. Looks straightfoward. Btw, I am developing an Android application. Integrating with Android will include working with JNI etc. My only concern might be whether it would be too heavy on a smartphone. Still looking for any optimization that can be done to the image before eye detection. |
2014-06-23 04:50:36 -0600 | asked a question | How to improve grayscale image quality for eye detection? Hei guys, Currently I am converting preview frames into grayscale using the codes below: I am using this preview frames for eye detection using haarcascades_eye.xml cascade classifier. Before passing the region of interest for eye detection, I'm doing some preprocessing as below: However, I find that the image produces is distorted as in "white washed" when the lighting is low and as a consequence, the eye detection is bad. Is there any preprocessing that can be done to enhance this images? Thanks. |
2014-04-29 09:32:23 -0600 | received badge | ● Editor (source) |
2014-04-29 09:31:57 -0600 | asked a question | How to use OpenCV face detection in portrait using byte[] data from onPreviewFrame()? Hi guys, I am trying to use OpenCV face detection using the the byte[] data obtained from the onPreviewFrame() method of the Camera.PreviewCallback I manage to convert the data into grayscale image using the codes below. and I have set android:screenOrientation to "portrait" in the AndroidManifest file. I am using OpenCV JavaDetector and drawing a rectangle over the faces detected using this However, in the resulting grayscale mat, face detection only happens when I hold my Android phone in landscape position. It does not work in portrait position. Is there any way to overcome this issue? I have used the Android FaceDetectionListener and that doesn't seem to have problem detecting faces in portrait mode. But, FaceDetectionListener's functions are limited compared to OpenCV. Any help would be greatly appreciated. Thx. |
2013-11-19 10:53:52 -0600 | asked a question | Why face detected is in OpenCV is not exactly surrounding face?? I am trying to do a face detection application. It receives data from from onPreviewFrame and process it in openCV. The problem is that when I convert it back to Bitmap to be displayed in Android, the rectangle for the face detected is not exactly surrounding the face. It is moved slightly downwards. So, the top of the rectangle is at below the nose and the bottom is at the bottom of the neck. My code are as below. |
2013-11-15 08:00:38 -0600 | asked a question | Face detection using OpenCV Java Android's camera onPreviewFrame()'s byte[] data does not work. I am trying to used OpenCV java wrapper to detect faces in an app. 1) The app is using front-facing camera in potrait mode. 2) The preview is displayed inside a SurfaceView. 3) I am using Android's onPreviewFrame()'s byte[] data and changing it into OpenCV format to detect the faces using OpenCV. 4) I send the coordinates detected by mJavaDetector to a View class to be drawn on a instance of the drawingView surface. When I start the application, there are no errors but no rectangle is drawn. The "Log.v(TAG, "Length of facesArray" + facesArray.length);" inside SurfaceChanged is also not displayed. Is it because the onPreviewFrame() is not called or a problem with my OpenCV implementation or other problems? I have attached my codes below. public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { private class DrawingView extends View{ My drawingView declaration in onCreate() |