2015-08-30 04:56:55 -0600 | commented answer | Null object reference while trying to show image on emulator, OpenCV4Android I tried to put the image in the folder "sdcard" but got the error: [2015-08-30 11:49:28] Failed to push selection: Read-only file system So I tried insted to put it in the folder "data", and that went just fine. So the pathdef should be this: "/mnt/data/my.jpg" ??? |
2015-08-30 04:56:18 -0600 | commented answer | Null object reference while trying to show image on emulator, OpenCV4Android I tried right now, but its gives the same error (which I expected, because it could read the height and width of the image correctly) |
2015-08-30 04:32:51 -0600 | asked a question | Null object reference while trying to show image on emulator, OpenCV4Android Hi! After installing Android Studio and setting up the OpenCv4Android 3.0, I tried to run a simple application which purpose was to read a image from the emulators hard disk and then show it in the app. Unfortunately I got the error "Null object reference". This is a sample of code I have been using: public class MainActivity extends AppCompatActivity { And this is how I declared the imgview object in the xml: ImageView android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/sampleImageView" android:layout_centerHorizontal="true" android:layout_toEndOf="@+id/textView" And this is the logcat: 08-30 08:50:26.925 2715-2715/com.example.robin.opencvexample I/OpenCV/StaticHelper﹕ ----------------------------------------------------------------- 08-30 08:50:26.925 2715-2715/com.example.robin.opencvexample I/opencv﹕ opencv initialization successful 08-30 08:50:27.051 2715-2715/com.example.robin.opencvexample I/opencv﹕ Image read successful, height: 350 width: 480 08-30 08:50:27.063 2715-2715/com.example.robin.opencvexample D/AndroidRuntime﹕ Shutting down VM 08-30 08:50:27.063 2715-2715/com.example.robin.opencvexample E/AndroidRuntime﹕ FATAL EXCEPTION: main Process: com.example.robin.opencvexample, PID: 2715 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.robin.opencvexample/com.example.robin.opencvexample.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView.setImageBitmap(android.graphics.Bitmap)' on a null object reference Conclusion: From reading the log, the image and the opencv was sucessfully initialized, and the height and width of the image is correct as well. But its when I try to show the image where it fails. Any suggestion? Regards Robin |