Ios 以OpenCV Mat格式从相机捕获静止图像

我正在开发一个iOS应用程序，并尝试使用捕获会话从相机获取静态图像快照，但我无法将其成功转换为OpenCV Mat

静态图像输出是使用以下代码创建的：

- (void)createStillImageOutput;
{
    // setup still image output with jpeg codec
    self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
    NSDictionary *outputSettings = [NSDictionary dictionaryWithObjectsAndKeys:AVVideoCodecJPEG, AVVideoCodecKey, nil];
    [self.stillImageOutput setOutputSettings:outputSettings];
    [self.captureSession addOutput:self.stillImageOutput];

    for (AVCaptureConnection *connection in self.stillImageOutput.connections) {
        for (AVCaptureInputPort *port in [connection inputPorts]) {
            if ([port.mediaType isEqual:AVMediaTypeVideo]) {
                self.videoCaptureConnection = connection;
                break;
            }
        }
        if (self.videoCaptureConnection) {
            break;
        }
    }
    NSLog(@"[Camera] still image output created");
}

[self.stillImageOutput captureStillImageAsynchronouslyFromConnection:self.videoCaptureConnection
                                                   completionHandler:
 ^(CMSampleBufferRef imageSampleBuffer, NSError *error)
 {
     if (error == nil && imageSampleBuffer != NULL)
     {
         NSData *jpegData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
     }

             UIImage* newImage = [UIImage imageWithData:jpegData];

然后尝试使用以下代码捕获静止图像：

- (void)createStillImageOutput;
{
    // setup still image output with jpeg codec
    self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
    NSDictionary *outputSettings = [NSDictionary dictionaryWithObjectsAndKeys:AVVideoCodecJPEG, AVVideoCodecKey, nil];
    [self.stillImageOutput setOutputSettings:outputSettings];
    [self.captureSession addOutput:self.stillImageOutput];

    for (AVCaptureConnection *connection in self.stillImageOutput.connections) {
        for (AVCaptureInputPort *port in [connection inputPorts]) {
            if ([port.mediaType isEqual:AVMediaTypeVideo]) {
                self.videoCaptureConnection = connection;
                break;
            }
        }
        if (self.videoCaptureConnection) {
            break;
        }
    }
    NSLog(@"[Camera] still image output created");
}

[self.stillImageOutput captureStillImageAsynchronouslyFromConnection:self.videoCaptureConnection
                                                   completionHandler:
 ^(CMSampleBufferRef imageSampleBuffer, NSError *error)
 {
     if (error == nil && imageSampleBuffer != NULL)
     {
         NSData *jpegData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
     }

             UIImage* newImage = [UIImage imageWithData:jpegData];

我需要一种基于缓冲区中的像素数据创建OpenCV Mat的方法。 我曾尝试使用以下代码创建垫子，这些代码取自OpenCV摄像机类摄像机：

但它无法在CVPixelBufferGetWidth或CVPixelBufferGetHeight调用上获取图像的实际高度和宽度，因此Mat的创建失败

我知道我可以使用以下代码基于像素数据创建UIImage：

- (void)createStillImageOutput;
{
    // setup still image output with jpeg codec
    self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
    NSDictionary *outputSettings = [NSDictionary dictionaryWithObjectsAndKeys:AVVideoCodecJPEG, AVVideoCodecKey, nil];
    [self.stillImageOutput setOutputSettings:outputSettings];
    [self.captureSession addOutput:self.stillImageOutput];

    for (AVCaptureConnection *connection in self.stillImageOutput.connections) {
        for (AVCaptureInputPort *port in [connection inputPorts]) {
            if ([port.mediaType isEqual:AVMediaTypeVideo]) {
                self.videoCaptureConnection = connection;
                break;
            }
        }
        if (self.videoCaptureConnection) {
            break;
        }
    }
    NSLog(@"[Camera] still image output created");
}

[self.stillImageOutput captureStillImageAsynchronouslyFromConnection:self.videoCaptureConnection
                                                   completionHandler:
 ^(CMSampleBufferRef imageSampleBuffer, NSError *error)
 {
     if (error == nil && imageSampleBuffer != NULL)
     {
         NSData *jpegData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
     }

             UIImage* newImage = [UIImage imageWithData:jpegData];

但我更喜欢直接构建CvMat，就像OpenCV CvVideoCamera类中的情况一样，因为我只对OpenCV中的图像感兴趣，我不想再次花费时间转换，也不想冒失去质量或方向问题的风险（无论如何，OpenCV提供的UIImagetoCV转换函数导致内存泄漏，无法释放内存）

请告知我如何获得OpenCV Mat的图像。

---

提前谢谢。

我已经找到了解决问题的方法

解决办法是：

通过在OpenCv Camera类中重写此方法：“createVideoPreviewLayer”

应该是这样的：

- (void)createVideoPreviewLayer;
{

    self.parentView.layer.sublayers = nil;
    if (captureVideoPreviewLayer == nil) {
        captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc]
        initWithSession:self.captureSession];
    }

    if (self.parentView != nil) {
        captureVideoPreviewLayer.frame = self.parentView.bounds;
        captureVideoPreviewLayer.videoGravity =
        AVLayerVideoGravityResizeAspectFill;
        [self.parentView.layer addSublayer:captureVideoPreviewLayer];
    }
    NSLog(@"[Camera] created AVCaptureVideoPreviewLayer");
}

您应该将这一行添加到“createVideoPreviewLayer”方法将解决的问题中 问题是：

self.parentView.layer.sublayers = nil;

您需要使用暂停方法而不是停止方法