OpenCV错误:空数组指针Java
我正在运行网络摄像头,试图实时检测物体,我已经运行了这段代码。它在OpenCV错误:空数组指针Java,java,opencv,nullpointerexception,Java,Opencv,Nullpointerexception,我正在运行网络摄像头,试图实时检测物体,我已经运行了这段代码。它在video.main(video.java:92)-CvRect sq=cvBoundingRect(ptr,0)处给出错误但是我正在检查如果(ptr!=null)。我不明白为什么 CvMemStorage storage = CvMemStorage.create(); CvSeq contours = new CvContour(null); noOfContors = cvFindContours(img
video.main(video.java:92)
-CvRect sq=cvBoundingRect(ptr,0)处给出错误代码>但是我正在检查如果(ptr!=null)
。我不明白为什么
CvMemStorage storage = CvMemStorage.create();
CvSeq contours = new CvContour(null);
noOfContors = cvFindContours(imgbin, storage, contours, Loader.sizeof(CvContour.class), CV_RETR_CCOMP, CV_CHAIN_APPROX_NONE, new CvPoint(0,0));
for (ptr = contours; ptr != null; ptr = ptr.h_next()) {
if(ptr != null){
CvRect sq = cvBoundingRect(ptr, 0);
if(sq.height()*sq.width() > minAreaa && sq.height()* sq.width() < maxAreaa){
p1.x(sq.x());
p2.x(sq.x()+sq.width());
p1.y(sq.y());
p2.y(sq.y()+sq.height());
cvRectangle(img1, p1, p2, CV_RGB(255, 0, 0), 2, 8, 0);
}
}
}
通过在for
循环中添加附加条件解决了问题,但仍不知道这是否是正确的处理方法:
CvSeq contours1 = new CvContour(null);
for (ptr = contours; ptr != null && cvFindContours(imgbin, storage, contours1, Loader.sizeof(CvContour.class), CV_RETR_CCOMP, CV_CHAIN_APPROX_NONE, new CvPoint(0,0)) != 0; ptr = ptr.h_next()){ .....
}
请改用以下方法:
for (ptr = contours; ptr != null && !ptr.isNull(); ptr = ptr.h_next()) {
这个!ptr.isNull()修复空指针错误。错误提到null
数组指针。
for (ptr = contours; ptr != null && !ptr.isNull(); ptr = ptr.h_next()) {