Call Mat.channels() : cv::Mat img(1,1,CV_8U,cvScalar(0)); std::cout<<img.channels(); Output: 1 which is the number of channels. Also, try: std::cout<<img.type(); Output: 0 which belongs to CV_8U (look here at line 542). Study file types_c.h for each define.
I also was trying to do the same thing, because of need to combining image processed with two libraries. And what I’ve tried to do is to put byte[] in to Mat instead of RGB value. And it worked! So what I did was: 1.Converted BufferedImage to byte array with: byte[] pixels = ((DataBufferByte) image.getRaster().getDataBuffer()).getData(); … Read more
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 << “matName” << someMatrixOfAnyType; //Close the file and release all the memory buffers file.release(); The file extension can be xml or yml. In both cases you get a small header that you can easily remove/parse, … Read more
Perhaps section 3 of this document will help: [link now broken] https://software.intel.com/sites/default/files/managed/2f/19/inde_opencv_3.0_arch_guide.pdf Specifically, section 3.1: A unified abstraction cv::UMat that enables the same APIs to be implemented using CPU or OpenCL code, without a requirement to call OpenCL accelerated version explicitly. These functions use an OpenCL-enabled GPU if exists in the system, and automatically switch … Read more
In OpenCV, if the image is of floating point type, then only those pixels can be visualized using imshow, which have value from 0.0 to 1.0, if the value is greater than 1.0, it will be shown as a white pixel and if less than 0.0, it will be shown as black pixel. To visualize … Read more
Utils.bitmapToMat converts an Android Bitmap to an OpenCV Mat. It requires a bitmap of type ARGB_8888 or RGB_565. import org.opencv.android.Utils; Mat mat = new Mat(); Bitmap bmp32 = bmp.copy(Bitmap.Config.ARGB_8888, true); Utils.bitmapToMat(bmp32, mat);
You did everything except copying the new pixel value back to the image. This line takes a copy of the pixel into a local variable: Vec3b color = image.at<Vec3b>(Point(x,y)); So, after changing color as you require, just set it back like this: image.at<Vec3b>(Point(x,y)) = color; So, in full, something like this: Mat image = img; … Read more
Here is how to create a DataFrame where each series is a row. For a single Series (resulting in a single-row DataFrame): series = pd.Series([1,2], index=[‘a’,’b’]) df = pd.DataFrame([series]) For multiple series with identical indices: cols = [‘a’,’b’] list_of_series = [pd.Series([1,2],index=cols), pd.Series([3,4],index=cols)] df = pd.DataFrame(list_of_series, columns=cols) For multiple series with possibly different indices: list_of_series = … Read more