java opencv图像处理学习

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我是靠谱客的博主鲤鱼夕阳，最近开发中收集的这篇文章主要介绍java opencv图像处理学习，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

项目 https://gitee.com/qingfeng2556/JavaOpencvTest

import org.opencv.core.*;
import org.opencv.highgui.HighGui;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;

import java.io.File;
import java.util.LinkedList;
import java.util.List;

import static org.opencv.core.Core.BORDER_DEFAULT;
import static org.opencv.core.CvType.*;

/**
* copyright (C), 2018-2019
* fileName Test
* author zhangx
* date 2019/3/1 14:44
* https://docs.opencv.org/
* description
*/
public class Test {

public String imagePrePath = "D:/tools/ideawork/JavaOpencvTest/dev/";
// public String opencvDllPath="D:/tools/opencv/build/java/x64/opencv_java400.dll";
public String opencvDllPath = "lib/x64/opencv_java400.dll";

// D:toolsopencvbuildjavax64
// -Djava.library.path=D:toolsopencvbuildjavax64
public static void main(String[] args) {
//D:toolsideaworkoem-serverJavaOpencvTest
new Test().testLogEnhance();

}

/**
* 图像增强算法基于对数Log变换的图像增强对数变换可以将图像的低灰度值部分扩展，显示出低灰度部分更多的细节，
* 将其高灰度值部分压缩，减少高灰度值部分的细节，从而达到强调图像低灰度部分的目的
*/
@Deprecated
public void testLogEnhance() {//待测试,无法转换，从c++没找到对应的java代码
setLibPath();
String imageStr = imagePrePath + "8.jpg";
Mat src = Imgcodecs.imread(imageStr);

src.convertTo(src, CV_32F);

Mat dst = new Mat(src.size(), CV_32F);

Core.log(src, dst);//这个地方报错
Core.normalize(dst, dst, 0, 255);
Core.convertScaleAbs(dst, dst);
HighGui.imshow("testLogEnhance原图", src);

dst.convertTo(src, CV_8UC3);
HighGui.imshow("testLogEnhance", dst);
HighGui.waitKey(0);
}

public void setLibPath () {
File file = new File(opencvDllPath);
System.load(file.getAbsolutePath());
}

/**
* 图像增强算法使用中心为5的8邻域拉普拉斯算子与图像卷积可以达到锐化增强图像的目的
*/
public void testTePuLaSiEnhance () {
setLibPath();
// setLibPath();
String imageStr = imagePrePath + "9.jpg";
Mat src = Imgcodecs.imread(imageStr);
Mat dst = new Mat();

HighGui.imshow("拉普拉斯算子原图", src);

Mat kernel = new MatOfFloat(0, -1, 0, 0, 5, 0, 0, -1, 0);
Imgproc.filter2D(src, dst, CvType.CV_8UC3, kernel);
HighGui.imshow("拉普拉斯算子2", dst);
HighGui.waitKey(0);

// Mat dst=new Mat();
// if(img.rows()>800||img.cols()>600){
// Imgproc.resize(img, dst, new Size(600, 800), 0, 0, Imgproc.INTER_AREA);
// img=dst;
// }

}

/**
* sobel算法，边缘检测
* https://www.cnblogs.com/skyfsm/p/6879265.html
* */
public void testSobel () {
setLibPath();
String imageStr = imagePrePath + "7.jpg";

Mat src = Imgcodecs.imread(imageStr);
if (src.empty()) {
System.err.println("Cannot read image: ");
System.exit(0);
}
Mat grad_x = new Mat();
Mat grad_y = new Mat();
Mat abs_grad_x = new Mat();
Mat abs_grad_y = new Mat();
Mat dst = new Mat();

//x方向梯度
Imgproc.Sobel(src, grad_x, CV_16S, 1, 0, 3, 1, 1, BORDER_DEFAULT);
Core.convertScaleAbs(grad_x, abs_grad_x);
HighGui.imshow("x方向", abs_grad_x);

Imgproc.Sobel(src, grad_y, CV_16S, 0, 1, 3, 1, 1, BORDER_DEFAULT);
Core.convertScaleAbs(grad_y, abs_grad_y);
HighGui.imshow("y方向", abs_grad_y);

Core.addWeighted(abs_grad_x, 0.5, abs_grad_y, 0.5, 0, dst);

HighGui.imshow("整体方向", dst);

HighGui.imshow("src", src);

HighGui.waitKey(0);

}

/**
* 图像旋转
* https://docs.opencv.org/4.0.0/d4/d61/tutorial_warp_affine.html
* */
public void testImageRotationMy () {
setLibPath();
String imageStr = imagePrePath + "1.jpg";

String filename = imageStr;
Mat src = Imgcodecs.imread(filename);
if (src.empty()) {
System.err.println("Cannot read image: " + filename);
System.exit(0);
}

//向左旋转90度,没有黑边
Point[] srcTri = new Point[3];
srcTri[0] = new Point(0, 0);
srcTri[1] = new Point(src.cols() - 1, 0);
srcTri[2] = new Point(0, src.rows() - 1);

Point[] dstTri = new Point[3];
dstTri[0] = new Point(0, src.cols() - 1);
dstTri[1] = new Point(0, 0);
dstTri[2] = new Point(src.rows() - 1, src.cols() - 1);

Mat warpMat = Imgproc.getAffineTransform(new MatOfPoint2f(srcTri), new MatOfPoint2f(dstTri));//转换使用
Mat warpDst = Mat.zeros(src.cols(), src.rows(), src.type());//转换成的结果
Imgproc.warpAffine(src, warpDst, warpMat, warpDst.size());

//向右旋转90度,有黑边
Point center = new Point(src.cols() / 2, src.rows() / 2);
double angle = -90.0;
double scale = 1;
Mat rotMat = Imgproc.getRotationMatrix2D(center, angle, scale);//翻转矩阵
Mat rotateMat = new Mat(src.cols(), src.rows(), src.type());
Imgproc.warpAffine(src, rotateMat, rotMat, src.size());

HighGui.imshow("Source image", src);
HighGui.imshow("Warp", warpDst);
HighGui.imshow("Warp + Rotate", rotateMat);
HighGui.waitKey(0);
System.exit(0);

}

/**
* 图像旋转
* */
public void testImageRotation () {
setLibPath();
String imageStr = imagePrePath + "1.jpg";

String filename = imageStr;
Mat src = Imgcodecs.imread(filename);
if (src.empty()) {
System.err.println("Cannot read image: " + filename);
System.exit(0);
}
Point[] srcTri = new Point[3];
srcTri[0] = new Point(0, 0);
srcTri[1] = new Point(src.cols() - 1, 0);
srcTri[2] = new Point(0, src.rows() - 1);

Point[] dstTri = new Point[3];
dstTri[0] = new Point(0, src.rows() * 0.33);
dstTri[1] = new Point(src.cols() * 0.85, src.rows() * 0.25);
dstTri[2] = new Point(src.cols() * 0.15, src.rows() * 0.7);

Mat warpMat = Imgproc.getAffineTransform(new MatOfPoint2f(srcTri), new MatOfPoint2f(dstTri));
Mat warpDst = Mat.zeros(src.rows(), src.cols(), src.type());
Imgproc.warpAffine(src, warpDst, warpMat, warpDst.size());
// Point center = new Point(warpDst.cols() / 2, warpDst.rows() / 2);

Point center = new Point(src.cols() / 2, src.rows() / 2);
double angle = -50.0;
double scale = 0.6;
Mat rotMat = Imgproc.getRotationMatrix2D(center, angle, scale);
Mat warpRotateDst = new Mat();
Imgproc.warpAffine(warpDst, warpRotateDst, rotMat, warpDst.size());
HighGui.imshow("Source image", src);
HighGui.imshow("Warp", warpDst);
HighGui.imshow("Warp + Rotate", warpRotateDst);
HighGui.waitKey(0);
System.exit(0);

}

/***
* 图像翻转 https://blog.csdn.net/jningwei/article/details/78753607
* flipCode 1 水平翻转 0 垂直翻转 -1 水平垂直翻转
*/
public void testImageFlip () {
setLibPath();
String imageStr = imagePrePath + "1.jpg";
Mat src = Imgcodecs.imread(imageStr);
Mat dst = new Mat();

HighGui.imshow("原图像", src);

Core.flip(src, dst, 1);

HighGui.imshow("水平翻转 ", dst);

dst = new Mat();
Core.flip(src, dst, 0);
HighGui.imshow("垂直翻转", dst);

dst = new Mat();
Core.flip(src, dst, -1);
HighGui.imshow("水平垂直翻转", dst);

HighGui.waitKey();

}

/**
* 直方图均衡化是通过调整图像的灰阶分布，使得在0~255灰阶上的分布更加均衡，提高了图像的对比度，
* 达到改善图像主观视觉效果的目的。对比度较低的图像适合使用直方图均衡化方法来增强图像细节。
*/
public void testHistogramEnhance () {
setLibPath();
String imageStr = imagePrePath + "8.jpg";
Mat src = Imgcodecs.imread(imageStr);
Mat dst = new Mat();

List<Mat> matList = new LinkedList<>();
matList.add(new Mat());
matList.add(new Mat());
matList.add(new Mat());
HighGui.imshow("原图像", src);
Core.split(src, matList);
for (int i = 0; i < 3; i++) {
Imgproc.equalizeHist(matList.get(i), matList.get(i));
}
Core.merge(matList, dst);

HighGui.imshow("直方图均衡化图像增强效果", dst);
HighGui.waitKey();
}

/**
* 图像缩放 https://blog.csdn.net/m1109048058/article/details/77069607
*/
public void testResize () {
setLibPath();
String imageStr = imagePrePath + "2.jpg";
File imgFile = new File(imageStr);
Mat src = Imgcodecs.imread(imageStr);
Mat dst = new Mat();
Imgproc.resize(src, dst, new Size(src.cols() / 2, src.rows() / 2), 0, 0, Imgproc.INTER_AREA);
Imgcodecs.imwrite(imagePrePath + "narrow.jpg", dst);

Mat endst = new Mat();
Imgproc.resize(src, endst, new Size(src.cols() * 2, src.rows() * 2), 0, 0, Imgproc.INTER_LINEAR);
Imgcodecs.imwrite(imagePrePath + "enlarge.jpg", endst);
}
}