ios – 使用边界捕获图像？

概述我可以从iOS后置摄像头捕捉图像.一切都在完美无瑕地工作,除了我希望它按照我的UIView中的界限拍摄照片. 我的代码如下： - (void)viewDidLoad{ [super viewDidLoad]; // Do any additional setup after loading the view. session = [[AVCaptureSession a 我可以从iOS后置摄像头捕捉图像.一切都在完美无瑕地工作,除了我希望它按照我的UIVIEw中的界限拍摄照片.

我的代码如下：

- (voID)vIEwDIDLoad{    [super vIEwDIDLoad];    // Do any additional setup after loading the vIEw.    session = [[AVCaptureSession alloc] init];    session.sessionPreset = AVCaptureSessionPresetMedium;    captureVIDeoPrevIEwLayer = [[AVCaptureVIDeoPrevIEwLayer alloc] initWithSession:session];    captureVIDeoPrevIEwLayer.vIDeoGravity = AVLayerVIDeoGravityResizeAspectFill;    captureVIDeoPrevIEwLayer.frame = vImagePrevIEw.bounds;    [vImagePrevIEw.layer addSublayer:captureVIDeoPrevIEwLayer];    AVCaptureDevice *device = [self backFacingCameraifAvailable];    NSError *error = nil;    AVCaptureDeviceinput *input = [AVCaptureDeviceinput deviceinputWithDevice:device error:&error];    if (!input) {        // Handle the error appropriately.        NSLog(@"ERROR: trying to open camera: %@",error);    }    [session addinput:input];    stillimageOutput = [[AVCaptureStillimageOutput alloc] init];    NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys: AVVIDeoCodecJPEG,AVVIDeoCodecKey,nil];    [stillimageOutput setoutputSettings:outputSettings];    AVCaptureConnection *vIDeoConnection = nil;    for (AVCaptureConnection *connection in stillimageOutput.connections) {        for (AVCaptureinputPort *port in [connection inputPorts]) {            if ([[port mediaType] isEqual:AVMediaTypeVIDeo] ) {                vIDeoConnection = connection;                break;            }        }        if (vIDeoConnection) {            break;        }    }    [session startRunning];    [session addOutput:stillimageOutput];}-(AVCaptureDevice *)backFacingCameraifAvailable{    NSArray *vIDeoDevices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVIDeo];    AVCaptureDevice *captureDevice = nil;    for (AVCaptureDevice *device in vIDeoDevices){        if (device.position == AVCaptureDevicepositionBack){            captureDevice = device;            break;        }    }    //  Couldn't find one on the back,so just get the default vIDeo device.    if (!captureDevice){        captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVIDeo];    }    return captureDevice;}

以下是捕获图像的代码：

- (IBAction)captureTask {    AVCaptureConnection *vIDeoConnection = nil;    for (AVCaptureConnection *connection in stillimageOutput.connections){        for (AVCaptureinputPort *port in [connection inputPorts]){            if ([[port mediaType] isEqual:AVMediaTypeVIDeo]){                vIDeoConnection = connection;                break;            }        }        if (vIDeoConnection) {            break;        }    }    NSLog(@"about to request a capture from: %@",stillimageOutput);    [stillimageOutput captureStillimageAsynchronouslyFromConnection:vIDeoConnection completionHandler: ^(CMSampleBufferRef imageSampleBuffer,NSError *error)     {         CFDictionaryRef exifAttachments = CMGetAttachment(imageSampleBuffer,kCGImagePropertyExifDictionary,NulL);         if (exifAttachments) {             // Do something with the attachments.             NSLog(@"attachements: %@",exifAttachments);         } else {             NSLog(@"no attachments");         }         NSData *imageData = [AVCaptureStillimageOutput jpegStillimageNSDataRepresentation:imageSampleBuffer];         UIImage *image = [[UIImage alloc] initWithData:imageData];         stillimage = image;     }];}

我面临的问题是,它正在拍摄照片,并保存到stillimage,但是,从我所知道的,该图像适用于整个iPhone屏幕.这不是我创建的UIVIEw * vImagePrevIEw的范围.有没有办法剪辑捕获图像的边界？

[编辑]

阅读文档后,我意识到图像是正确的分辨率,如下所示：session.sessionPreset = AVCaptureSessionPresetMedium;.有没有办法让图像像一个正方形？就像Instagram制作图像一样？根据文档的所有会话预设都不是所有正方形:(

我试过以下：

captureVIDeoPrevIEwLayer.vIDeoGravity = AVLayerVIDeoGravityResize;

但是,它仅调整图像大小以适合当前视图,不会生成方形图像.

解决方法 我理解你的沮丧,预设应该是可定制的或有更多的选择！我对我的图像所做的就是围绕中心裁剪它们,我为此编写了以下代码：

- (UIImage *)crop:(UIImage *)image from:(CGSize)src to:(CGSize)dst{    CGPoint cropCenter = CGPointMake((src.wIDth/2),(src.height/2));    CGPoint cropStart = CGPointMake((cropCenter.x - (dst.wIDth/2)),(cropCenter.y - (dst.height/2)));    CGRect cropRect = CGRectMake(cropStart.x,cropStart.y,dst.wIDth,dst.height);    CGImageRef cropRef = CGImageCreateWithImageInRect(image.CGImage,cropRect);    UIImage* cropImage = [UIImage imageWithCGImage:cropRef];    CGImageRelease(cropRef);    return cropImage;}

其中src表示原始尺寸,dst表示裁剪尺寸;和图像当然是你想要裁剪的图像.

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