java - 在 javacv 中将 IplImage 转换为 Mat

Question

我需要帮助将我的转换IplImage为Mat. 我想计算HOGDescriptor我的图像，然后用 SVM 对其进行分类，但“计算”需要Mat类型。

你能举一些如何在java中IplImage转换的例子吗？Mat

Answer 1

将 IplImage 转换为 Mat 很简单。

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

Mat matImage = new Mat(iplImage);

反之亦然

Answer 2

不要混淆此处记录的官方 OpenCV Java 绑定和没有文档的JavaCV项目。

如果您正在使用JavaCV，则无需转换IplImage即可使用HOGDescriptor，正如您在JavaCV源代码中看到的那样，HOGDescriptor对象包装器操作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，正如您在 中看到的opencv_core.java，IplImage包装器对象扩展了CvArr：

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

所以你不应该做任何转换。

这是一个使用示例HOGDescriptor.detectMultiScale：

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 3

有一个方法：

opencv_core.cvarrToMat(iplImage);