opencv+java图形识别
x业精于勤x 人气:0前言
OpenCV的 全称是:Open Source Computer Vision Library。OpenCV是一个基于BSD许可(开源)发行的跨平台计算机视觉库,可以运行在Linux、Windows、Android和Mac OS操作系统上。它轻量级而且高效——由一系列 C 函数和少量 C++ 类 构成,同时提供了Python、Ruby、MATLAB等语言的接口,实现了 图像处理和计算机视觉方面的很多通用算法。
OpenCV用C++语言编写,它的主要接口也是C++语言,但是依然保留了大量的C语言接口。该库也有大量的Python, Java and MATLAB/OCTAVE (版本2.5)的接口。这些语言的API接口函数可以通过在线文档获得。如今也提供对于C#,Ch, Ruby的支持。
本文着重讲述opencv+java的实现程序,关于opencv的如何引入dll库等操作以及c的实现就不在这里概述了
方法如下
直接开始,首先下载opencv,引入opencv-246.jar包以及对应dll库
1.背景去除 简单案列,只适合背景单一的图像
import java.util.ArrayList; import java.util.List; import org.opencv.core.Core; import org.opencv.core.CvType; import org.opencv.core.Mat; import org.opencv.core.Point; import org.opencv.core.Scalar; import org.opencv.core.Size; import org.opencv.highgui.Highgui; import org.opencv.imgproc.Imgproc; /** * @Description 背景去除 简单案列,只适合背景单一的图像 * @author XPY * @date 2016年8月30日下午4:14:32 */ public class demo1 { public static void main(String[] args) { System.loadLibrary("opencv_java246"); Mat img = Highgui.imread("E:\\opencv_img\\source\\1.jpg");//读图像 Mat new_img = doBackgroundRemoval(img); Highgui.imwrite("E:\\opencv_img\\target\\1.jpg",new_img);//写图像 } private static Mat doBackgroundRemoval(Mat frame) { // init Mat hsvImg = new Mat(); List<Mat> hsvPlanes = new ArrayList<>(); Mat thresholdImg = new Mat(); int thresh_type = Imgproc.THRESH_BINARY_INV; // threshold the image with the average hue value hsvImg.create(frame.size(), CvType.CV_8U); Imgproc.cvtColor(frame, hsvImg, Imgproc.COLOR_BGR2HSV); Core.split(hsvImg, hsvPlanes); // get the average hue value of the image Scalar average = Core.mean(hsvPlanes.get(0)); double threshValue = average.val[0]; Imgproc.threshold(hsvPlanes.get(0), thresholdImg, threshValue, 179.0, thresh_type); Imgproc.blur(thresholdImg, thresholdImg, new Size(5, 5)); // dilate to fill gaps, erode to smooth edges Imgproc.dilate(thresholdImg, thresholdImg, new Mat(), new Point(-1, -1), 1); Imgproc.erode(thresholdImg, thresholdImg, new Mat(), new Point(-1, -1), 3); Imgproc.threshold(thresholdImg, thresholdImg, threshValue, 179.0, Imgproc.THRESH_BINARY); // create the new image Mat foreground = new Mat(frame.size(), CvType.CV_8UC3, new Scalar(255, 255, 255)); thresholdImg.convertTo(thresholdImg, CvType.CV_8U); frame.copyTo(foreground, thresholdImg);// 掩膜图像复制 return foreground; } }
2.边缘检测
import org.opencv.core.Core; import org.opencv.core.Mat; import org.opencv.core.Size; import org.opencv.highgui.Highgui; import org.opencv.imgproc.Imgproc; /** * @Description 边缘检测 * @author XPY * @date 2016年8月30日下午5:01:01 */ public class demo2 { public static void main(String[] args) { System.loadLibrary(Core.NATIVE_LIBRARY_NAME); Mat img = Highgui.imread("E:\\face7.jpg");//读图像 Mat new_img = doCanny(img); Highgui.imwrite("E:\\opencv_img\\target\\2.jpg",new_img);//写图像 } private static Mat doCanny(Mat frame) { // init Mat grayImage = new Mat(); Mat detectedEdges = new Mat(); double threshold = 10; // convert to grayscale Imgproc.cvtColor(frame, grayImage, Imgproc.COLOR_BGR2GRAY); // reduce noise with a 3x3 kernel Imgproc.blur(grayImage, detectedEdges, new Size(3, 3)); // canny detector, with ratio of lower:upper threshold of 3:1 Imgproc.Canny(detectedEdges, detectedEdges, threshold, threshold * 3); // using Canny's output as a mask, display the result Mat dest = new Mat(); frame.copyTo(dest, detectedEdges); return dest; } }
3.人脸检测技术 (靠边缘的和侧脸检测不准确)
import org.opencv.core.Core; import org.opencv.core.Mat; import org.opencv.core.MatOfRect; import org.opencv.core.Point; import org.opencv.core.Rect; import org.opencv.core.Scalar; import org.opencv.highgui.Highgui; import org.opencv.objdetect.CascadeClassifier; /** * * @Description 人脸检测技术 (靠边缘的和侧脸检测不准确) * @author XPY * @date 2016年9月1日下午4:47:33 */ public class demo3 { public static void main(String[] args) { System.out.println("Hello, OpenCV"); // Load the native library. System.loadLibrary("opencv_java246"); new demo3().run(); } public void run() { System.out.println("\nRunning DetectFaceDemo"); System.out.println(getClass().getResource("/haarcascade_frontalface_alt2.xml").getPath()); // Create a face detector from the cascade file in the resources // directory. //CascadeClassifier faceDetector = new CascadeClassifier(getClass().getResource("haarcascade_frontalface_alt2.xml").getPath()); //Mat image = Highgui.imread(getClass().getResource("lena.png").getPath()); //注意:源程序的路径会多打印一个‘/',因此总是出现如下错误 /* * Detected 0 faces Writing faceDetection.png libpng warning: Image * width is zero in IHDR libpng warning: Image height is zero in IHDR * libpng error: Invalid IHDR data */ //因此,我们将第一个字符去掉 String xmlfilePath=getClass().getResource("/haarcascade_frontalface_alt2.xml").getPath().substring(1); CascadeClassifier faceDetector = new CascadeClassifier(xmlfilePath); Mat image = Highgui.imread("E:\\face2.jpg"); // Detect faces in the image. // MatOfRect is a special container class for Rect. MatOfRect faceDetections = new MatOfRect(); faceDetector.detectMultiScale(image, faceDetections); System.out.println(String.format("Detected %s faces", faceDetections.toArray().length)); // Draw a bounding box around each face. for (Rect rect : faceDetections.toArray()) { Core.rectangle(image, new Point(rect.x, rect.y), new Point(rect.x + rect.width, rect.y + rect.height), new Scalar(0, 255, 0)); } // Save the visualized detection. String filename = "E:\\faceDetection.png"; System.out.println(String.format("Writing %s", filename)); System.out.println(filename); Highgui.imwrite(filename, image); } }
人脸检测需要自行下载haarcascade_frontalface_alt2.xml文件
附上demo下载地址:点击这里,运行需自行引入opencv的dll文件
总结
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