目前我正在开发一个Android应用程序，它可以在运行时查找相机预览中最大的矩形（检测页面或矩形对象）并对其执行OCR。我在运行时检测图像有问题。它显示以下错误。
FATAL EXCEPTION: main Process: sansys.helpinghands, PID: 978 CvException [org.opencv.core.CvException: cv::Exception: /Volumes/Linux/builds/master_pack-android/opencv/modules/imgproc/src/color.cpp:8282: error: (-215) sz.width % 2 == 0 && sz.height % 3 == 0 && depth == CV_8U in function void cv::cvtColor(cv::InputArray, cv::OutputArray, int, int) ]
at org.opencv.imgproc.Imgproc.cvtColor_0(Native Method)
at org.opencv.imgproc.Imgproc.cvtColor(Imgproc.java:1715)
at sansys.helpinghands.CameraPreview.processFrame(CameraPreview.java:201)
at sansys.helpinghands.CameraPreview.onPreviewFrame(CameraPreview.java:65)
at android.hardware.Camera$EventHandler.handleMessage(Camera.java:1129)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5443)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
我在下面提供了我的代码。
CAMERA PREVIEW CLASS
public class CameraPreview implements SurfaceHolder.Callback, Camera.PreviewCallback {
private Camera mCamera = null;
private ImageView MyCameraPreview = null;
private Bitmap bitmap, bmp = null;
private int[] pixels = null;
private byte[] FrameData = null;
private int imageFormat;
private int PreviewSizeWidth;
private int PreviewSizeHeight;
private boolean bProcessing = false;
private Mat mYuv;
Handler mHandler = new Handler(Looper.getMainLooper());
public CameraPreview(int PreviewlayoutWidth, int PreviewlayoutHeight, ImageView CameraPreview) {
PreviewSizeWidth = PreviewlayoutWidth;
PreviewSizeHeight = PreviewlayoutHeight;
MyCameraPreview = CameraPreview;
mYuv = new Mat(PreviewlayoutHeight + PreviewlayoutWidth / 2, PreviewlayoutWidth, CvType.CV_8UC1);
Log.v("-------------------->", "" + mYuv.channels());
pixels = new int[PreviewSizeWidth * PreviewSizeHeight];
}
@Override
public void onPreviewFrame(byte[] arg0, Camera arg1) {
// At preview mode, the frame data will push to here.
if (imageFormat == ImageFormat.NV21) {
// We only accept the NV21(YUV420) format.
if (!bProcessing) {
FrameData = arg0;
this.processFrame(arg0);
bmp = processFrame(arg0);
mHandler.post(DoImageProcessing);
}
}
}
public void onPause() {
mCamera.stopPreview();
}
@Override
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
Camera.Parameters parameters;
parameters = mCamera.getParameters();
// Set the camera preview size
parameters.setPreviewSize(PreviewSizeWidth, PreviewSizeHeight);
imageFormat = parameters.getPreviewFormat();
mCamera.setParameters(parameters);
mCamera.startPreview();
}
@Override
public void surfaceCreated(SurfaceHolder arg0) {
mCamera = Camera.open();
try {
// If did not set the SurfaceHolder, the preview area will be black.
mCamera.setPreviewDisplay(arg0);
mCamera.setPreviewCallback(this);
} catch (IOException e) {
mCamera.release();
mCamera = null;
}
}
@Override
public void surfaceDestroyed(SurfaceHolder arg0) {
mCamera.setPreviewCallback(null);
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
static {
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
}
private Runnable DoImageProcessing = new Runnable() {
public void run() {
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
// Mat mat = Imgcodecs.imdecode(new MatOfByte(FrameData), Imgcodecs.CV_LOAD_IMAGE_UNCHANGED);
Mat tmp = new Mat(bitmap.getHeight(), bitmap.getWidth(), CvType.CV_8UC3);
bitmap = Bitmap.createBitmap(PreviewSizeWidth, PreviewSizeHeight, Bitmap.Config.ARGB_8888);
Log.i("MyRealTimeImageProcess", "DoImageProcessing():");
bProcessing = true;
bitmap.sameAs(bmp);
Utils.bitmapToMat(bitmap, tmp);
Log.v("qweedfdfbfdbf", tmp.width() + "" + tmp.height());
// detection d = new detection(PreviewSizeWidth, PreviewSizeHeight, FrameData, pixels);
detection d = new detection();
MatOfPoint point = null;
try {
point = d.find(tmp);
} catch (Exception e) {
e.printStackTrace();
}
// MatOfPoint c=d.detection_result();
List<MatOfPoint> contours = new ArrayList<>();
contours.add(point);
MatOfPoint2f approxCurve = new MatOfPoint2f();
for (int i = 0; i < contours.size(); i++) {
Imgproc.drawContours(tmp, contours, i, new Scalar(255, 255, 255), -1);
}
};
};
protected Bitmap processFrame(byte[] data) {
Mat mRgba = new Mat();
mYuv.put(0, 0, data);
Imgproc.cvtColor(mYuv, mRgba, Imgproc.COLOR_YUV420sp2RGB, 4);
//process mat with native code
Utils.matToBitmap(mRgba, bitmap);
return bitmap;
}
}
检测课程
public class detection {
private MatOfPoint contour;
private Mat mat;
detection(int h, int w, byte[] b, int[] p) {
Mat mat = Imgcodecs.imdecode(new MatOfByte(b), Imgcodecs.CV_LOAD_IMAGE_UNCHANGED);
try {
this.contour = this.find(mat);
} catch (Exception e) {
e.printStackTrace();
}
}
detection(Mat m) {
this.mat = m;
}
MatOfPoint detection_result() {
return this.contour;
}
detection() {}
public static double angle(Point p1, Point p2, Point p0) {
double dx1 = p1.x - p0.x;
double dy1 = p1.y - p0.y;
double dx2 = p2.x - p0.x;
double dy2 = p2.y - p0.y;
return (dx1 * dx2 + dy1 * dy2) / Math.sqrt((dx1 * dx1 + dy1 * dy1) * (dx2 * dx2 + dy2 * dy2) + 1e-10);
}
public static MatOfPoint find(Mat src) throws Exception {
Mat blurred = src.clone();
Imgproc.medianBlur(src, blurred, 9);
Mat gray0 = new Mat(blurred.size(), CvType.CV_8U), gray = new Mat();
List<MatOfPoint> contours = new ArrayList<>();
List<Mat> blurredChannel = new ArrayList<>();
blurredChannel.add(blurred);
List<Mat> gray0Channel = new ArrayList<>();
gray0Channel.add(gray0);
MatOfPoint2f approxCurve;
double maxArea = 0;
int maxId = -1;
for (int c = 0; c < 3; c++) {
int ch[] = {c, 0};
Core.mixChannels(blurredChannel, gray0Channel, new MatOfInt(ch));
int thresholdLevel = 1;
for (int t = 0; t < thresholdLevel; t++) {
if (t == 0) {
Imgproc.Canny(gray0, gray, 10, 20, 3, true); // true ?
Imgproc.dilate(gray, gray, new Mat(), new Point(-1, -1), 1); // 1 ?
} else {
Imgproc.adaptiveThreshold(gray0, gray, thresholdLevel, Imgproc.ADAPTIVE_THRESH_GAUSSIAN_C, Imgproc.THRESH_BINARY, (src.width() + src.height()) / 200, t);
}
Imgproc.findContours(gray, contours, new Mat(), Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE);
for (MatOfPoint contour : contours) {
MatOfPoint2f temp = new MatOfPoint2f(contour.toArray());
double area = Imgproc.contourArea(contour);
approxCurve = new MatOfPoint2f();
Imgproc.approxPolyDP(temp, approxCurve, Imgproc.arcLength(temp, true) * 0.02, true);
if (approxCurve.total() == 4 && area >= maxArea) {
double maxCosine = 0;
List<Point> curves = approxCurve.toList();
for (int j = 2; j < 5; j++) {
double cosine = Math.abs(angle(curves.get(j % 4), curves.get(j - 2), curves.get(j - 1)));
maxCosine = Math.max(maxCosine, cosine);
}
if (maxCosine < 0.3) {
maxArea = area;
maxId = contours.indexOf(contour);
//contours.set(maxId, getHull(contour));
}
}
}
}
}
if (maxId >= 0) {
return contours.get(maxId);
//Imgproc.drawContours(src, contours, maxId, new Scalar(255, 0, 0, .8), 8);
}
return null;
}
public static void main(String args[]) throws Exception {
}
}