converting cv::Mat for tesseract

Question

I\'m using OpenCV to extract a subimage of a scanned document and would like to use tesseract to perform OCR over this subimage.

I found out that I can use two meth

Answer 1

For Anybody using the JavaCPP presets of OpenCV/Tesseract, here is what works

Mat img = imread("file.jpg");
Mat gray = new Mat();
cvtColor(img, gray, CV_BGR2GRAY);

// api is a Tesseract client which is initialised

api.SetImage(gray.data().asBuffer(),gray.size().width(),gray.size().height(),gray.channels(),gray.size1())