opencv for android 矩形检测

整个项目的结构图：

编写森段并DetectFaceDemo.java,代码如下：

[java] view

plaincopyprint?

package com.njupt.zhb.test

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

//

// Detects faces in an image, draws boxes around them, and writes the results

// to "faceDetection.png".

//

public class DetectFaceDemo {

public void run() {

System.out.println("\nRunning DetectFaceDemo")

System.out.println(getClass().getResource("lbpcascade_frontalface.xml").getPath())

// Create a face detector from the cascade file in the resources

// directory.

//CascadeClassifier faceDetector = new CascadeClassifier(getClass().getResource("lbpcascade_frontalface.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‘/’，因此总是出现燃竖如下错误

/*

* 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，我此迹们将第一个字符去掉

String xmlfilePath=getClass().getResource("lbpcascade_frontalface.xml").getPath().substring(1)

CascadeClassifier faceDetector = new CascadeClassifier(xmlfilePath)

Mat image = Highgui.imread(getClass().getResource("we.jpg").getPath().substring(1))

// 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 = "faceDetection.png"

System.out.println(String.format("Writing %s", filename))

Highgui.imwrite(filename, image)

}

}

package com.njupt.zhb.test

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

//

// Detects faces in an image, draws boxes around them, and writes the results

// to "faceDetection.png".

//

public class DetectFaceDemo {

public void run() {

System.out.println("\nRunning DetectFaceDemo")

System.out.println(getClass().getResource("lbpcascade_frontalface.xml").getPath())

// Create a face detector from the cascade file in the resources

// directory.

//CascadeClassifier faceDetector = new CascadeClassifier(getClass().getResource("lbpcascade_frontalface.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("lbpcascade_frontalface.xml").getPath().substring(1)

CascadeClassifier faceDetector = new CascadeClassifier(xmlfilePath)

Mat image = Highgui.imread(getClass().getResource("we.jpg").getPath().substring(1))

// 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 = "faceDetection.png"

System.out.println(String.format("Writing %s", filename))

Highgui.imwrite(filename, image)

}

}

3.编写测试类：

[java] view

plaincopyprint?

package com.njupt.zhb.test

public class TestMain {

public static void main(String[] args) {

System.out.println("Hello, OpenCV")

// Load the native library.

System.loadLibrary("opencv_java246")

new DetectFaceDemo().run()

}

}

//运行结果:

//Hello, OpenCV

//

//Running DetectFaceDemo

///E:/eclipse_Jee/workspace/JavaOpenCV246/bin/com/njupt/zhb/test/lbpcascade_frontalface.xml

//Detected 8 faces

//Writing faceDetection.png

package com.njupt.zhb.test

public class TestMain {

public static void main(String[] args) {

System.out.println("Hello, OpenCV")

// Load the native library.

System.loadLibrary("opencv_java246")

new DetectFaceDemo().run()

}

}

//运行结果:

//Hello, OpenCV

//

//Running DetectFaceDemo

///E:/eclipse_Jee/workspace/JavaOpenCV246/bin/com/njupt/zhb/test/lbpcascade_frontalface.xml

//Detected 8 faces

//Writing faceDetection.png

如果这带烂个是摆正的矩形，就是说没有偏角，那就只要找到左上角坐标和长，宽,然后设置一个mask，复制出来就行。但是这个点坐标和长宽不好确定。对你这个图，我提供一种办法吧，你可以试试，以歼行神前项目遇到过，肯定能行。你用轮廓检测，然后对所有内轮廓经行循环找到最大的一个内轮廓，获取这个最大的轮廓，然后设置一张和这个氏亏原图一样的全0图，在这张全0图片上画出那个你找到轮廓的内填充域，画完的这个作为你的mask，最后用个copy函数把mask里面的复制下来就行啦。

方法有点笨，但是很实用，楼主可以试试~~·话说去年遇到过类似情况，几个师兄弟一起讨论来讨论去，最后还是这个套路OPENCV能实现。如有更好的方法可以说来交流一下~~希望您能帮到你。

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