在Android中使用OpenCv 来处…-CFANZ编程社区

最近在研究在用C来处理图片，后来再网上找了一下，有的说用libjpeg和opencv来处理图片。先研究一下，opencv来处理图片，

这是网上一位友人写的代码http://blogold.chinaunix.net/u1/57901/showart.php?id=2512389

开始之前，先编译opencv得到 libandroid-opencv.so库，请参考这位牛人的博客javascript:void(0)

1、创建一个android工程,工程名为opencvtest,包名为com.opencvtest

在工程的根目录下创建一个jni文件夹,然后分别创建Android.mk和hello-jni.cpp两个文件

Android.mk的内容如下:

1. # date: Summer, 2010    
2. # author: Ethan Rublee   
3. # contact: ethan.rublee@gmail.com   
4. #   
5. := $(call my-dir)  
6.  
7. $(CLEAR_VARS)  
8.  
9. #OPENCV_ROOT must be defined.   
10. OPENCV_ROOT  
11. Please define OPENCV_ROOT to point to the root folder of opencv, try ndk-build OPENCV_ROOT=../../opencv)  
12.  
13. Defaulting to OPENCV_ROOT=$(OPENCV_ROOT))  
14. endif  
15.  
16.  
17. #define OPENCV_INCLUDES   
18. $(OPENCV_ROOT)/includes.mk  
19. #define OPENCV_LIBS   
20. $(OPENCV_ROOT)/libs.mk  
21.  
22. += $(OPENCV_LIBS)  
23.      
24. +=  $(OPENCV_INCLUDES) $(ANDROID_OPENCV_INCLUDES)  
25.  
26.    := hello-jni  
27.  
28. := hello-jni.cpp  
29.  
30. $(BUILD_SHARED_LIBRARY)

2、hello-jni.cpp

1. #include    
2. #include    
3. #include    
4. #include    
5.  
6. #include    
7. #include    
8. #include    
9. #include    
10. #include    
11. #include    
12.  
13.  
14. static CvScalar colors[]=  
15.  
16.            {{0,0,255}},  
17.            {{0,128,255}},  
18.            {{0,255,255}},  
19.            {{0,255,0}},  
20.            {{255,128,0}},  
21.            {{255,255,0}},  
22.            {{255,0,0}},  
23.            {{255,0,255}},  
24.            {{255,255,255}}  
25.  
26. };  
27.  
28. extern "C"  
29. Java_com_opencv_ActivityMain_getKeypointNum(JNIEnv* env,jobject thiz)  
30. {  
31.    IplImage* object = cvLoadImage("/sdcard/camera.jpg",CV_LOAD_IMAGE_GRAYSCALE);  
32.     if(object != NULL){  
33.            CvSURFParams params = cvSURFParams(500, 1);  
34.            CvMemStorage* storage = cvCreateMemStorage(0);  
35.            IplImage* object_color = cvCreateImage(cvGetSize(object), 8, 3);  
36.            CvSeq *objectKeypoints = 0;  
37.            CvSeq *objectDescriptors = 0;  
38.  
39.            cvCvtColor( object, object_color, CV_GRAY2BGR );  
40.            cvExtractSURF( object, 0, &objectKeypoints, &objectDescriptors, storage, params);  
41.  
42.         for( int i = 0; i < objectKeypoints->total; i++ )  
43.         {  
44.         CvSURFPoint* r = (CvSURFPoint*)cvGetSeqElem( objectKeypoints, i );  
45.         CvPoint center;  
46.         int radius;  
47.         center.x = cvRound(r->pt.x);  
48.         center.y = cvRound(r->pt.y);  
49.         radius = cvRound(r->size*1.2/9.*2);  
50.         cvCircle( object_color, center, radius, colors[0], 1, 8, 0 );  
51.         }  
52.  
53.            cvSaveImage( "/sdcard/src_surf.jpg" , object_color);  
54.  
55.            return objectKeypoints->total;  
56.        }  
57.  
58.     return 0;  
59.  
60.  
61.

#include

3、ActivityMain.java

1. package com.opencv;  
2.  
3. import android.app.Activity;  
4. import android.os.Bundle;  
5. import android.widget.TextView;  
6.  
7. public class ActivityMain extends Activity {  
8.      
9.      
10.    private TextView text;  
11.      
12.    @Override  
13.    public void onCreate(Bundle savedInstanceState) {  
14.        super.onCreate(savedInstanceState);  
15.        setContentView(R.layout.main);  
16.          
17.        text = (TextView) findViewById(R.id.text);  
18.        text.setText(Integer.toString(getKeypointNum()));  
19.          
20.    }  
21.      
22.    public native int getKeypointNum();  
23.      
24.    static  
25.    {  
26.          
27.        System.loadLibrary("hello-jni");  
28.    }  
29.      
30.      
31.

4、把这个工程编译了,工程结构

在Android中使用OpenCv 来处…_#define

5、效果如图：原图

在Android中使用OpenCv 来处…_#define

效果图：

在Android中使用OpenCv 来处…_#define

6、注意，如果处理大的图片的时候会出现异常。没有响应，不知道是什么问题！求高手解答