MainCarRemoteControl/app/src/main/cpp/ocr_text.cpp

//
// Created by UnknownObject on 2022/11/4.
// Copyright (c) 2022 UnknownNetworkService. All rights reserved.
//

//OCR的图像预处理算法

#include "ocr_text.h"

namespace uns
{
	//像素检查，limit阈值是黑色的浓淡（文字是图片中最黑的部分）
	bool OCRSupport::PixelCheck(const cv::Vec3b &pixel)
	{
		if (pixel[0] <= limit)
			if (pixel[1] <= limit)
				if (pixel[2] <= limit)
					return true;
		return false;
	}
	
	//图片裁切
	cv::Mat OCRSupport::CutImageSize(const cv::Mat &img)
	{
		return img(roi);
	}
	
	//图片预处理，将彩色图片转换为黑白图片，确保文字是黑色的
	cv::Mat OCRSupport::ConvertImage(const cv::Mat &img)
	{
		cv::imwrite("/sdcard/MainCar/OCR/ocr_old.jpg", img);
		cv::Mat result(img.size(), img.type());
		for (int r = 0; r < img.rows; r++)
		{
			for (int c = 0; c < img.cols; c++)
			{
				if (PixelCheck(img.at<cv::Vec3b>(r, c)))
					result.at<cv::Vec3b>(r, c) = cv::Vec3b(0, 0, 0);
				else
					result.at<cv::Vec3b>(r, c) = cv::Vec3b(255, 255, 255);
			}
		}
		cv::imwrite("/sdcard/MainCar/OCR/ocr_process.jpg", result);
		return result;
	}
};

//导出的自检函数
extern "C" JNIEXPORT
jstring JNICALL Java_com_uns_maincar_cpp_1interface_EnvTest_OCRTextTest(JNIEnv *env, jclass _this)
{
	std::string version = "OCR Text Library Found, Version: " + std::string(OCR_TEXT_VERSION);
	return env->NewStringUTF(version.c_str());
}

//导出的图像预处理函数
extern "C" JNIEXPORT
jobject JNICALL
Java_com_uns_maincar_cpp_1interface_OCR_ProcessImage(JNIEnv *env, jclass _this, jobject image,
													 jboolean self_test)
{
	cv::Mat source;
	uns::OCRSupport ocr_supp;
	BitmapToMat(env, image, source);
	cv::Mat img = (self_test ? ocr_supp.ConvertImage(source) : ocr_supp.ConvertImage(
			ocr_supp.CutImageSize(source)));
	jobject bmp = GenerateBitmap(env, img.cols, img.rows);
	MatToBitmap(env, img, bmp);
	return bmp;
}