Question

我正在使用OpenCV在iOS上进行实时视频处理，而不使用CvVideoCamera。我的应用程序因内存压力而崩溃。

本机iOS相机每次捕获帧时都会调用此函数：

- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
       fromConnection:(AVCaptureConnection *)connection
{
    //convert the frame to a UIImage:
    UIImage *image = [self imageFromSampleBuffer:sampleBuffer];

    //convert the UIImage to a Mat:
    Mat srcMat = [self cvMatFromUIImage:image];

    //Process the Mat:
    Mat dst, cdst;
    Canny(srcMat, dst, 50, 200, 3);
    cvtColor(dst, cdst, COLOR_GRAY2BGR);
}

由于内存压力，应用程序在15秒后崩溃。

我正在使用Apple's code for imageFromSampleBuffer:和OpenCV's code for cvMatFromUIImage。是的，我正在使用ARC。

我使用Allocations Instrument分析了应用程序，发现崩溃是由于大量UIImage被创建并且从未发布。经过一些调查后，我发现对Canny()的调用对此负责，因为当UIImage的调用被注释掉时，Canny()个对象不会泄漏。

为什么调用Canny使UIImage个对象留在内存中？

Answer 1

- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
       fromConnection:(AVCaptureConnection *)connection
{

    CFRetain(sampleBuffer);

    dispatch_queue_t myQueue = dispatch_queue_create("my.dispatch.q", 0);
    dispatch_async(myQueue,
    ^{
        //convert the frame to a UIImage:
        UIImage *image = [self imageFromSampleBuffer:sampleBuffer];

        //convert the UIImage to a Mat:
        Mat srcMat = [self cvMatFromUIImage:image];

        //Process the Mat:
        Mat dst, cdst;
        Canny(srcMat, dst, 50, 200, 3);
        cvtColor(dst, cdst, COLOR_GRAY2BGR);
        CFRelease(sampleBuffer);
    });
}

OpenCV代码导致UIImages泄漏

1 个答案: