将IplImage转换为javacv中的Mat

Question

我需要帮助将我的IplImage转换为Mat。我想为我的图像计算HOGDescriptor，然后用SVM对其进行分类，但“计算”需要Mat类型。

你可以举一些如何在java中将IplImage转换为Mat的例子吗？

Answer 1

请不要混淆和JavaCV项目没有文档的official OpenCV Java binding。

如果您使用JavaCV，你不需要你IplImage转换才能使用HOGDescriptor，你可以在JavaCV source看到，HOGDescriptor对象包装操纵CvArr对象：

// javacv/cpp/opencv_objdetect.java:527 
public static class HOGDescriptor extends Pointer { 
    public HOGDescriptor(); 
    ... 
    public native void setSVMDetector(CvArr _svmdetector); 
    ... 
    public native void compute(CvArr img, FloatPointer descriptors, CvSize winStride, CvSize padding, CvPoint locations); 
    public native void detect(CvArr img, CvPoint foundLocations, DoublePointer weights, double hitThreshold, CvSize winStride, CvSize padding, CvPoint searchLocations); 
    public native void detect(CvArr img, CvPoint foundLocations, double hitThreshold, CvSize winStride, CvSize padding, CvPoint searchLocations); 
    public native void detectMultiScale(CvArr img, CvRect foundLocations, double hitThreshold, CvSize winStride, CvSize padding, double scale, int groupThreshold); 
    public native void detectMultiScale(CvArr img, CvRect foundLocations, DoublePointer foundWeights, double hitThreshold, CvSize winStride, CvSize padding, double scale, double finalThreshold, boolean useMeanshiftGrouping); 
    public native void detectMultiScale(CvArr img, CvRect foundLocations, double hitThreshold, CvSize winStride, CvSize padding, double scale, double finalThreshold, boolean useMeanshiftGrouping); 
    ... 
}; 

现在，你可以在opencv_core.java看到，IplImage包装对象扩展CvArr：

// javacv/cpp/opencv_core.java:410 
public static class IplImage extends CvArr { 
    ... 
}; 

所以你不应该做任何转换。

下面是使用HOGDescriptor.detectMultiScale一个例子：

IplImage img = cvLoadImage("image.jpg"); 
CvRect foundRects = new CvRect(null); 
HOGDescriptor hog = new HOGDescriptor(); 
FloatPointer svm = HOGDescriptor.getDefaultPeopleDetector(); 
hog.setSVMDetector(svm); 
hog.detectMultiScale(img, foundRects, 0, cvSize(8,8), cvSize(32,32), 1.05, 2); 

Answer 2

转换的IplImage到太简单。

IplImage iplImage= cvLoadImage("image.png"); 

Mat matImage = new Mat(iplImage); 

反之亦然

Answer 3

有一个方法是：

opencv_core.cvarrToMat(iplImage);