在iOS5中从CIImage创建UIImage时遇到问题 [英] Having trouble creating UIImage from CIImage in iOS5

问题描述

我正在使用AVFoundation框架。在我的示例缓冲区委托中，我有以下代码：

I'm using the AVFoundation framework. In my sample buffer delegate I have the following code:

-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection{
     CVPixelBufferRef pb = CMSampleBufferGetImageBuffer(sampleBuffer);
     CIImage *ciImage = [CIImage imageWithCVPixelBuffer:pb];
     self.imageView.image = [UIImage imageWithCIImage:ciImage];
}

我可以使用CIImage来运行面部检测器等但是它没有出现在UIImageView中... imageView保持白色。关于这个问题的任何想法？
我使用以下设置我的会话：

I am able to use the CIImage to run the face detector etc. but it does not show up in the UIImageView ... the imageView remains white. Any ideas as to the problem? I am using the following to setup my session:

    self.session = [[AVCaptureSession alloc] init];
self.session.sessionPreset = AVCaptureSessionPreset640x480;
self.videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
self.videoInput = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:nil]; 
self.frameOutput = [[AVCaptureVideoDataOutput alloc] init];
self.frameOutput.videoSettings = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:kCVPixelFormatType_32BGRA] forKey:(id)kCVPixelBufferPixelFormatTypeKey];

推荐答案

这可能有所帮助。我使用此代码遇到了同样的问题（图像没有被绘制到屏幕上）：

This might help. I was having the same issue (image not being drawn to screen) with this code:

CIImage *image = [[CIImage alloc] initWithImage:[UIImage imageNamed:@"mushroom.jpg"]];

theImageView.image = [UIImage imageWithCIImage:image];

但是，将代码更改为此后，它现在可以正常工作：

However, after changing the code to this, it now works correctly:

CIImage *image = [[CIImage alloc] initWithImage:[UIImage imageNamed:@"mushroom.jpg"]];

CIContext *context = [CIContext contextWithOptions:nil];

theImageView.image = [UIImage imageWithCGImage:[context createCGImage:image fromRect:image.extent]];

要了解有关CIContext的更多信息，请查看此处：
http://developer.apple。 com / library / ios /＃DOCUMENTATION / GraphicsImaging / Reference / QuartzCoreFramework / Classes / CIContext_Class / Reference / Reference.html＃// apple_ref / occ / cl / CIContext

To read more about CIContext take a look here: http://developer.apple.com/library/ios/#DOCUMENTATION/GraphicsImaging/Reference/QuartzCoreFramework/Classes/CIContext_Class/Reference/Reference.html#//apple_ref/occ/cl/CIContext

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