mat

问题 I would like to write a function in JNI like this: JNIEXPORT jobject JNICALL Java_com_datumdroid_android_ocr_simple_HoughLine_nativeDetectLine (JNIEnv * jenv, jclass, jstring fileInput, jobject mat) The Java interface would be : nativeDetectLine( String fileInput, Mat mat); Now I want to pass the Mat to JNI and change its value. Can anyone give me a tutorial or guide? Specifically how work with jobjects. 回答1: http://answers.opencv.org/question/12271/can-the-java-interface-pass-a-mat-to

问题 I am wondering about the way of accessing data in Mat in OpenCV. As you know, we can access to get data in many ways. I want to store image (Width x Height x 1-depth) in Mat and looping access each pixel in the image. Using ptr<>(irow) to get row-pixel and then access each column in the row is the best way? or using at<>(irow,jcol) is the best? or using directly calculate the index by using index = irow*Width + jrow is the best? Anyone know the reason. Thanks in advance 回答1: You can find

问题 I read a lot about memory leaks with Bitmaps but I can't solve my problem. I have an app works fine in my phone, but in others I'm getting the outOfMemoryError bitmap size exceeds VM. My problem is that I don't understand how to free this resources. I have a game with several activities and dialog with drawables in background in XML files, sometimes as a layout background and sometimes as a ImageView to fullscreen. How I can free this memory? I can't use recycle, I'm use unbindDrawables

问题 Im attempting to analyze a memory leak that has been driving me crazy for weeks, I found out about the eclipse MAT tool that helps you to figure out what is wrong, the problem is every single tutorial I have found says that I need to convert the format of the file from dalvik to HPROF format, however not one single tutorial I can find explains how to actually do it, instead I get vague things like this Now the file you will get does not conform to the "standard" Sun .hprof format but is

问题 I've been searching on an answer but all I can find is the inverse of what I need (Mat to FIBITMAP). I have a short code that loads images as FIBITMAP objects. I need FreeImage because OpenCV doesn't allow me to load pfm and some other extension files. What I'm trying to do is convert the FIBTMAP image into an OpenCV Mat so that I can use this in a much longer code I already have. How do I do? 回答1: The funtion FI2MAT will perform the conversion from FreeImage to OpenCV Mat. I cannot

问题 So I make a bitmap from a blob with the next code: byte[] blob = contact.getMP(); ByteArrayInputStream inputStream = new ByteArrayInputStream(blob); Bitmap bitmap = BitmapFactory.decodeStream(inputStream); Bitmap scalen = Bitmap.createScaledBitmap(bitmap, 320, 240, false); and it gives back the next output, which is good Then I do the following to make the bitmap into a Mat, but then my colors just change... //Mat ImageMat = new Mat(); Mat ImageMat = new Mat(320, 240, CvType.CV_32F); Utils

问题 Mat b = new Mat(); Bitmap bmp = getIntent().getExtras().getParcelable("image_send"); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_display_image); Mat tmp = new Mat (bmp.getWidth(), bmp.getHeight(), CvType.CV_8UC1); Utils.bitmapToMat(bmp, tmp); Imgproc.cvtColor(tmp, tmp, Imgproc.COLOR_RGB2GRAY); //Imgproc.cvtColor(tmp, tmp, Imgproc.COLOR_GRAY2RGB, 4); Utils.matToBitmap(tmp, bmp); iv = (ImageView)

问题 I have a matrix Mat B(480,640,CV_32FC1); containing floating values..I want to write this matrix to a file which could be opened in notepad or Ms word or Excel to see the values inside and for storage....imwrite function can save 8-bit or 16-bit image only.. Drop in your suggestions if this could be done?? if yes, how ?? 回答1: Using pure OpenCV API calls: // Declare what you need cv::FileStorage file("some_name.ext", cv::FileStorage::WRITE); cv::Mat someMatrixOfAnyType; // Write to file! file

问题 I'm trying to implement a streaming service using OpenCV and sockets. The server side loads a given image and sends it to the client, which receives it through the socket and displays it. I'm having a lot of trouble, though, sending the data of the image and reconstructing it on the client side. This is the code I've made so far: Image sender: #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h>

问题 How can I convert a BufferedImage to a Mat in OpenCV? Im using the java wrapper for OpenCV(not JavaCV). As I am new to OpenCV I have some problems understanding how Mat works. I want to do something like this. (Based on Ted W. reply): BufferedImage image = ImageIO.read(b.getClass().getResource("Lena.png")); int rows = image.getWidth(); int cols = image.getHeight(); int type = CvType.CV_16UC1; Mat newMat = new Mat(rows,cols,type); for(int r=0; r<rows; r++){ for(int c=0; c<cols; c++){ newMat