Advanced denoise Image using Opencv - opencv

Question

I am trying denoise this image to get better edges
I've tried bilaterFilter, GaussianBlur, morphological close and several threshold but every time I get an image like:
and when I do the HoughLinesP with dilatation of edges is really bad result.
Can some one help me to improve this? Is there a some way to take out those noise?
Frist try: using GaussianBlur, in this case, I must use equalizeHist or I cant get edges even if I use a really low threshold
public class TesteNormal {
static {
System.loadLibrary("opencv_java310");
}
public static void main(String args[]) {
Mat imgGrayscale = new Mat();
Mat imgBlurred = new Mat();
Mat imgCanny = new Mat();
Mat image = Imgcodecs.imread("c:\\cordova\\imagens\\teste.jpg", 1);
int imageWidth = image.width();
int imageHeight = image.height();
Imgproc.cvtColor(image, imgGrayscale, Imgproc.COLOR_BGR2GRAY);
Imgproc.equalizeHist(imgGrayscale, imgGrayscale);
Imgproc.GaussianBlur(imgGrayscale, imgBlurred, new Size(5, 5), 1.8);
Photo.fastNlMeansDenoising(imgBlurred, imgBlurred);
Imshow.show(imgBlurred);
Mat imgKernel = Imgproc.getStructuringElement(Imgproc.MORPH_CROSS, new Size(3, 3));
Imgproc.Canny(imgBlurred, imgCanny, 0, 80);
Imshow.show(imgCanny);
Imgproc.dilate(imgCanny, imgCanny, imgKernel, new Point(-1, -1), 2);
Imgproc.erode(imgCanny, imgCanny, imgKernel, new Point(-1, -1), 1);
Imshow.show(imgCanny);
Mat lines = new Mat();
int threshold = 100;
int minLineSize = imageWidth < imageHeight ? imageWidth / 3 : imageHeight / 3;
int lineGap = 5;
Imgproc.HoughLinesP(imgCanny, lines, 1, Math.PI / 360, threshold, minLineSize, lineGap);
System.out.println(lines.rows());
for(int x = 0; x < lines.rows(); x++) {
double[] vec = lines.get(x, 0);
double x1 = vec[0], y1 = vec[1], x2 = vec[2], y2 = vec[3];
Point start = new Point(x1, y1);
Point end = new Point(x2, y2);
Imgproc.line(image, start, end, new Scalar(255, 0, 0), 1);
}
Imshow.show(image);
}
}
Second try: using bilateral filter:
public class TesteNormal {
static {
System.loadLibrary("opencv_java310");
}
public static void main(String args[]) {
Mat imgBlurred = new Mat();
Mat imgCanny = new Mat();
Mat image = Imgcodecs.imread("c:\\cordova\\imagens\\teste.jpg", 1);
int imageWidth = image.width();
int imageHeight = image.height();
Imgproc.bilateralFilter(image, imgBlurred, 10, 35, 35);
Imshow.show(imgBlurred);
Mat imgKernel = Imgproc.getStructuringElement(Imgproc.MORPH_CROSS, new Size(3, 3));
Imgproc.Canny(imgBlurred, imgCanny, 0, 120);
Imshow.show(imgCanny);
Imgproc.dilate(imgCanny, imgCanny, imgKernel, new Point(-1, -1), 2);
Imgproc.erode(imgCanny, imgCanny, imgKernel, new Point(-1, -1), 1);
Imshow.show(imgCanny);
Mat lines = new Mat();
int threshold = 100;
int minLineSize = imageWidth < imageHeight ? imageWidth / 3 : imageHeight / 3;
int lineGap = 5;
Imgproc.HoughLinesP(imgCanny, lines, 1, Math.PI / 360, threshold, minLineSize, lineGap);
System.out.println(lines.rows());
for(int x = 0; x < lines.rows(); x++) {
double[] vec = lines.get(x, 0);
double x1 = vec[0], y1 = vec[1], x2 = vec[2], y2 = vec[3];
Point start = new Point(x1, y1);
Point end = new Point(x2, y2);
Imgproc.line(image, start, end, new Scalar(255, 0, 0), 1);
}
Imshow.show(image);
}
}
As suggested, I am trying use opencv contrib, using StructuredEdgeDetection. I am testing using a fixed image.
Frist I compile opencv with contrib
Segund I wrote the C++ code:
JNIEXPORT jobject JNICALL Java_vi_pdfscanner_main_ScannerEngine_getRandomFlorest(JNIEnv *env, jobject thiz) {
Mat mbgra = imread("/storage/emulated/0/Resp/coco.jpg", 1);
Mat3f fsrc;
mbgra.convertTo(fsrc, CV_32F, 1.0 / 255.0); // when I run those convertTo, I got all back image, that way I got no edges.
const String model = "/storage/emulated/0/Resp/model.yml.gz";
Ptr<cv::ximgproc::StructuredEdgeDetection> pDollar = cv::ximgproc::createStructuredEdgeDetection(model);
Mat edges;
__android_log_print(ANDROID_LOG_VERBOSE, APPNAME, "chamando edges");
pDollar->detectEdges(fsrc, edges);
imwrite( "/storage/emulated/0/Resp/edges.jpg", edges);
jclass java_bitmap_class = (jclass)env->FindClass("android/graphics/Bitmap");
jmethodID mid = env->GetMethodID(java_bitmap_class, "getConfig", "()Landroid/graphics/Bitmap$Config;");
jobject bitmap_config = env->CallObjectMethod(bitmap, mid);
jobject _bitmap = mat_to_bitmap(env,edges,false,bitmap_config);
return _bitmap;
}
and I wrote this java wapper
public class ScannerEngine {
private static ScannerEngine ourInstance = new ScannerEngine();
public static ScannerEngine getInstance() {
return ourInstance;
}
private ScannerEngine() {
}
public native Bitmap getRandomFlorest(Bitmap bitmap);
static {
System.loadLibrary("opencv_java3");
System.loadLibrary("Scanner");
}
}
this point is, when I run those lines
Mat mbgra = imread("/storage/emulated/0/Resp/coco.jpg", 1); //image is ok
Mat3f fsrc;
mbgra.convertTo(fsrc, CV_32F, 1.0 / 255.0); //now image got all back, someone have some ideia why?
Thanks very much!

Answer 1

The Result about are strong, like this
Original Image:
http://prntscr.com/cyd8qi
Edges Image:
http://prntscr.com/cyd9ax
Its run on android 4.4 (api lvl 19) in a really old device.
That's all,
Thanks you very much