Milepost digits detection

MilepostOCR.cpp

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/opencv.hpp>
#include <tesseract/baseapi.h>
#include <leptonica/allheaders.h>

std::string extractIntegerFromString(string str)
{
	std::string result;
	std::stringstream ss;
	ss << str[0];
	for (int i = 1; i < str.size(); i++) {
		ss << ' ' << str[i];
	}

	/* Store the String into String Stream */
	/* Running loop till the end of the stream */
	string tempStr;
	int found;
	while (ss >> tempStr) {

		/* Checking the given whether word is integer or not */
		if (stringstream(tempStr) >> found) {
			result += std::to_string(found);
		}

	}
	return result;
}
int main()
{
	cv::Mat img, resized, threshTop, threshBot, dilated, outTop, outBot;
	char *outText;
	std::string ocrOutput, finalOutput;

	tesseract::TessBaseAPI *api = new tesseract::TessBaseAPI();
	// Initialize tesseract-ocr with English, without specifying tessdata path
	if (api->Init(NULL, "eng")) {
		fprintf(stderr, "Could not initialize tesseract.\n");
		exit(1);
	}

	// Open input image with leptonica library
	img = cv::imread("C:/Users/super/OneDrive/Desktop/roadmark/crop.jpg",0);
	cv::resize(img, resized, cv::Size(4 * img.cols, 4 * img.rows));
	cv::Rect topRoi = cv::Rect(0, 0, resized.cols, resized.rows / 2);
	cv::Rect botRoi = cv::Rect(0, resized.rows / 2, resized.cols, resized.rows / 2);
	cv::threshold(resized(topRoi), threshTop, 128, 255, cv::THRESH_BINARY_INV);
	cv::threshold(resized(botRoi), threshBot, 128, 255, cv::THRESH_BINARY);

	cv::dilate(threshTop, dilated, cv::Mat(), cv::Point(-1, -1), 3, 1, 1);
	outTop = dilated.clone();
	outBot = threshBot.clone();

	api->SetPageSegMode(tesseract::PSM_SINGLE_LINE);

	api->SetImage((uchar*)outTop.data, outTop.size().width, outTop.size().height, outTop.channels(), outTop.step1());
	ocrOutput = api->GetUTF8Text();
	finalOutput += extractIntegerFromString(ocrOutput);

	api->SetImage((uchar*)outBot.data, outBot.size().width, outBot.size().height, outBot.channels(), outBot.step1());
	ocrOutput = api->GetUTF8Text();
	finalOutput += '.'+extractIntegerFromString(ocrOutput);
	
	std::cout << finalOutput;

	cv::namedWindow("out top", cv::WINDOW_AUTOSIZE);
	cv::namedWindow("clean", cv::WINDOW_AUTOSIZE);
	cv::namedWindow("out bot", cv::WINDOW_AUTOSIZE);
	cv::imshow("out top", outTop);
	cv::imshow("clean", threshTop);
	cv::imshow("out bot", outBot);
	cv::waitKey(0);
	cv::destroyAllWindows();

	// Destroy used object and release memory
	api->End();
	//delete[] outText;
	img.release();

	return 0;
}