在Android中使用的JavaCV中，在将Frame转换为IplImage以对视频应用色彩效果时，我们是NullPointerException.NPE仅在视频中的某些帧中遇到。
...
while (true) {
Log.d("JAVA_CV", "Counting . . . " + count);
Frame original_frame = ffg.grab();
if (original_frame == null) {
Log.d("JAVA_CV", "original_frame is NULL at" + count);
break;
} else {
Log.d("JAVA_CV", "original_frame is NOT_NULL at" + count);
if (converter == null) {
Log.d("JAVA_CV", "converter is null at position" +count);
continue;
}
opencv_core.IplImage frame1 = null;
if (original_frame != null) {
frame1 = converter.convertToIplImage(original_frame);
} else {
continue;
}
if (frame1 == null) {
Log.d("JAVA_CV", "frame1 is NULL at" + count);
} else {
if (!frame1.isNull() && original_frame.image != null) {
int width = frame1.width();
int height = frame1.height();
int channel = frame1.nChannels();
opencv_core.IplImage frame2 = opencv_core.IplImage.create(width, height, opencv_core.IPL_DEPTH_8U, channel);
if (frame2 == null)
continue;
opencv_core.cvCopy(frame1, frame2);
opencv_core.IplImage frame3 = opencv_core.IplImage.create(width, height, opencv_core.IPL_DEPTH_8U, 1);
if (frame3 == null)
continue;
opencv_imgproc.cvCvtColor(frame2, frame3, opencv_imgproc.CV_BGRA2GRAY);
Log.d("JAVA_CV", "frame1 is NOT_NULL at" + count + " Height " + frame1.height());
Frame resultFrame = converter.convert(frame3);
if (resultFrame == null)
continue;
recorder.record(resultFrame);
frame1.release();
frame2.release();
frame3.release();
original_frame = null;
} else {
break;
}
}
}
count++;
}
...
异常堆栈在这里：
06-20 12:00:57.664 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ java.lang.NullPointerException: This pointer address is NULL.
06-20 12:00:57.664 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ at org.bytedeco.javacpp.opencv_core$IplImage.width(Native Method)
06-20 12:00:57.664 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ at org.bytedeco.javacv.OpenCVFrameConverter.isEqual(OpenCVFrameConverter.java:75)
06-20 12:00:57.664 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ at org.bytedeco.javacv.OpenCVFrameConverter.convertToIplImage(OpenCVFrameConverter.java:85)
06-20 12:00:57.664 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ at org.bytedeco.javacv.OpenCVFrameConverter$ToIplImage.convert(OpenCVFrameConverter.java:41)
06-20 12:00:57.664 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ at com.appxperts.opencvfirstapp.MainActivitySecond.kaamdg(MainActivitySecond.java:161)
06-20 12:00:57.664 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ at com.appxperts.opencvfirstapp.MainActivitySecond$1.onClick(MainActivitySecond.java:62)
06-20 12:00:57.665 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ at android.view.View.performClick(View.java:4463)
06-20 12:00:57.665 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ at android.view.View$PerformClick.run(View.java:18789)
06-20 12:00:57.665 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ at android.os.Handler.handleCallback(Handler.java:808)
06-20 12:00:57.665 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ at android.os.Handler.dispatchMessage(Handler.java:103)
06-20 12:00:57.665 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ at android.os.Looper.loop(Looper.java:193)`enter code here`
06-20 12:00:57.665 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ at android.app.ActivityThread.main(ActivityThread.java:5299)
06-20 12:00:57.665 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ at java.lang.reflect.Method.invokeNative(Native Method)
06-20 12:00:57.665 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ at java.lang.reflect.Method.invoke(Method.java:515)
06-20 12:00:57.665 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:825)
06-20 12:00:57.665 30245-30245/com.appxperts.opencvfirstapp W/System.err﹕ at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:641)