ios - 如何使用叠加调整捕获的图像

Question

我想像立方体狗的工作原理一样实时捕获带有叠加层的图像 -按照此处http://www.musicalgeometry.com/?p=1681完成下面的代码

我知道如何在预览层中叠加图像并捕获图像，我查看了 Apple 示例代码，如果在相机胶卷中检测到人脸，它会保存一个红色方框。

编辑：

我想将其保存为 1920 X 1080 用于后置摄像头和 1280 X 960，下面的代码可以实时保存叠加层和图像，但是对齐已关闭，我不知道为什么有人可以帮忙？

干杯

这是预览层

这是在捕获之后

- (id)init {
    if ((self = [super init])) {
        [self setCaptureSession:[[AVCaptureSession alloc] init]];
        [self.captureSession setSessionPreset:AVCaptureSessionPresetHigh];
    }
    NSLog(@"init called");
    return self;
}


-(void)takePictureWithOverlay:(UIImage*)overlay andRect:(CGRect)overlayRect
{
    // Find out the current orientation and tell the still image output.
    AVCaptureConnection *stillImageConnection = [self.stillImageOutput connectionWithMediaType:AVMediaTypeVideo];

    //UIDeviceOrientation curDeviceOrientation = [[UIDevice currentDevice] orientation];
    // AVCaptureVideoOrientation avcaptureOrientation = [self avOrientationForDeviceOrientation:curDeviceOrientation];

    [stillImageConnection setVideoOrientation:AVCaptureVideoOrientationPortrait];

    [stillImageConnection setVideoScaleAndCropFactor:self.effectiveScale];

    [self.stillImageOutput captureStillImageAsynchronouslyFromConnection:stillImageConnection
                                                       completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
                                                           if (error) {
                                                               [self displayErrorOnMainQueue:error withMessage:@"Take picture failed"];
                                                           }
                                                           else {
                                                               // trivial simple JPEG case
                                                               NSData *jpegData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];

                                                               UIImage *image = [[UIImage alloc] initWithData:jpegData];

                                                               /////
                                                               CGSize imageSize = [image size];
                                                               CGSize overlaySize = [overlay size];

                                                               UIGraphicsBeginImageContext(imageSize);

                                                               [image drawInRect:CGRectMake(0, 0, imageSize.width, imageSize.height)];

                                                               NSLog(@"aaa %f", [UIScreen mainScreen].applicationFrame.size.width);
                                                               NSLog(@"aaa %f", [UIScreen mainScreen].applicationFrame.size.height);
                                                               NSLog(@"aaa %f", [[UIScreen mainScreen] bounds].size.height);

                                                               CGFloat xScaleFactor = imageSize.width / 320;//320;
                                                               CGFloat yScaleFactor = imageSize.height / 568;//480;//568;

                                                              NSLog(@"xScaleFactor size %F",xScaleFactor);
                                                               NSLog(@"yScaleFactor size %F",yScaleFactor);              

                                                               //144 for 568
                                                               [overlay drawInRect:CGRectMake(overlayRect.origin.x * xScaleFactor, overlayRect.origin.y*yScaleFactor
                                                                                              , overlaySize.width * xScaleFactor, overlaySize.height * yScaleFactor)]; // rect used in AROverlayViewController was (30,100,260,200)
                                                               UIImage *combinedImage = UIGraphicsGetImageFromCurrentImageContext();
                                                               [self setStillImage:combinedImage];
                                                               UIGraphicsEndImageContext();
                                                                /////
                                                           }
                                                           [[NSNotificationCenter defaultCenter] postNotificationName:kImageCapturedSuccessfully object:nil];

                                                       }];


}

Answer 1

从这里找到我的答案。http://developer.apple.com/library/ios/#qa/qa1714/_index.html

// Render the UIView into the CGContextRef using the
// CALayer/-renderInContext: method
- (void)renderView:(UIView*)view inContext:(CGContextRef)context
{
    // -renderInContext: renders in the coordinate space of the layer,
    // so we must first apply the layer's geometry to the graphics context
    CGContextSaveGState(context);
    // Center the context around the window's anchor point
    CGContextTranslateCTM(context, [view center].x, [view center].y);
    // Apply the window's transform about the anchor point
    CGContextConcatCTM(context, [view transform]);
    // Offset by the portion of the bounds left of and above the anchor point
    CGContextTranslateCTM(context,
                          -[view bounds].size.width * [[view layer] anchorPoint].x,
                          -[view bounds].size.height * [[view layer] anchorPoint].y);

    // Render the layer hierarchy to the current context
    [[view layer] renderInContext:context];

    // Restore the context
    CGContextRestoreGState(context);
}

-(void)takePictureWithOverlay:(UIView *)overlay andRect:(CGRect)overlayRect
{
    // Find out the current orientation and tell the still image output.
    self.videoConnection  = [self.stillImageOutput connectionWithMediaType:AVMediaTypeVideo];

    //UIDeviceOrientation curDeviceOrientation = [[UIDevice currentDevice] orientation];
    // AVCaptureVideoOrientation avcaptureOrientation = [self avOrientationForDeviceOrientation:curDeviceOrientation];

    [self.videoConnection  setVideoOrientation:AVCaptureVideoOrientationPortrait];

    [self.videoConnection  setVideoScaleAndCropFactor:self.effectiveScale];

    [self.stillImageOutput captureStillImageAsynchronouslyFromConnection:self.videoConnection
                                                       completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
                                                           if (error) {
                                                               [self displayErrorOnMainQueue:error withMessage:@"Take picture failed"];
                                                           }
                                                           else {
                                                               // trivial simple JPEG case
                                                               NSData *jpegData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];

                                                               UIImage *image = [[UIImage alloc] initWithData:jpegData];
                                                               NSLog(@"cgsize of image %@", NSStringFromCGSize(image.size));
                                                               CGSize imageSize = [[UIScreen mainScreen] bounds].size;
                                                               NSLog(@"cgsize %@", NSStringFromCGSize(imageSize));

                                                               UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0);
                                                               CGContextRef context = UIGraphicsGetCurrentContext();
                                                               // Draw the image returned by the camera sample buffer into the context.
                                                               // Draw it into the same sized rectangle as the view that is displayed on the screen.
                                                                  float menubarUIOffset = 200.0;
                                                                  UIGraphicsPushContext(context);
                                                                  [image drawInRect:CGRectMake(0, 0, imageSize.width, imageSize.height)];
                                                                  UIGraphicsPopContext();

                                                               // Render the camera overlay view into the graphic context that we created above.
                                                                  [self renderView:overlay inContext:context];

                                                               //Retrieve the screenshot image containing both the camera content and the overlay view
                                                               UIImage *screenshot = UIGraphicsGetImageFromCurrentImageContext();
                                                               [self setStillImage:screenshot];
                                                               UIGraphicsEndImageContext();
                                                                /////
                                                           }
                                                           [[NSNotificationCenter defaultCenter] postNotificationName:kImageCapturedSuccessfully object:nil];

                                                       }];


}