Question

使用iPhone 4的前置摄像头拍摄照片时，拍摄的照片与iPhone屏幕上显示的照片相比较。如何恢复UIImage（不是UIImageView）的“屏幕”视图，并能够像这样保存它？

我试过了：

UIImage* transformedImage = [UIImage imageWithCGImage:pickedImage.CGImage scale:1.0 orientation:UIImageOrientationLeftMirrored];
UIImageWriteToSavedPhotosAlbum (transformedImage, self, @selector(photoSaved:didFinishSavingWithError:contextInfo:), nil);

然后把它放在屏幕上。它与屏幕上显示的几乎相同，但保存的图像失真。

所以...我怎样才能恢复UIImage（不是UIImageView）的“屏幕”视图，并能够像这样保存它？

我也尝试过这种方式：

UIImage* pickedImage = [[info objectForKey:UIImagePickerControllerOriginalImage] retain];
UIImage* transformedImage;

CGSize imageSize = pickedImage.size;
UIGraphicsBeginImageContextWithOptions(imageSize, YES, 1.0);
GContextRef ctx = UIGraphicsGetCurrentContext();

CGContextRotateCTM(ctx, 3.14);  // rotate by 180°
CGContextScaleCTM(ctx, 1.0, -1.0); // flip vertical
CGContextDrawImage(ctx, CGRectMake(0.0, 0.0, imageSize.width, imageSize.height), pickedImage.CGImage);
transformedImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

但这只是一个黑色的图像。

Answer 1

- (void)didTakePicture:(UIImage *)picture
{
    UIImage * flippedImage = [UIImage imageWithCGImage:picture.CGImage scale:picture.scale orientation:UIImageOrientationLeftMirrored];
    picture = flippedImage;
}

Answer 2

我知道这个问题已经回答了，但上面的答案对我不起作用，以防有其他人......

UIImage *theImage = [info objectForKey:UIImagePickerControllerOriginalImage];
    if (picker.cameraDevice == UIImagePickerControllerCameraDeviceFront) {
        CGSize imageSize = theImage.size;
        UIGraphicsBeginImageContextWithOptions(imageSize, YES, 1.0);
        CGContextRef ctx = UIGraphicsGetCurrentContext();
        CGContextRotateCTM(ctx, M_PI/2);
        CGContextTranslateCTM(ctx, 0, -imageSize.width);
        CGContextScaleCTM(ctx, imageSize.height/imageSize.width, imageSize.width/imageSize.height);
        CGContextDrawImage(ctx, CGRectMake(0.0, 0.0, imageSize.width, imageSize.height), theImage.CGImage);
        UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
    }

和newImage是具有向上方向的新图像

Answer 3

最好的方法是将图像绘制到新的上下文中。

CGSize imageSize = pickedImage.size;
UIGraphicsBeginImageContextWithOptions(imageSize, YES, 1.0);
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(ctx, imageSize.width, 0.0);
CGContextScaleCTM(ctx, -1.0, 1.0);
CGContextDrawImage(ctx, pickedImage.CGImage, CGRectMake(0.0, 0.0, imageSize.width, imageSize.height));
UIImage *transformedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum (transformedImage, self, @selector(photoSaved:didFinishSavingWithError:contextInfo:), nil);

这是内存写的，没有编译器的帮助，请不要复制和粘贴......

Answer 4

安德鲁·帕克的回答很有效。这是Swift版本。

func flipImage(image: UIImage!) -> UIImage! {
    let imageSize:CGSize = image.size;
    UIGraphicsBeginImageContextWithOptions(imageSize, true, 1.0);
    let ctx:CGContextRef = UIGraphicsGetCurrentContext()!;
    CGContextRotateCTM(ctx, CGFloat(M_PI/2.0));
    CGContextTranslateCTM(ctx, 0, -imageSize.width);
    CGContextScaleCTM(ctx, imageSize.height/imageSize.width, imageSize.width/imageSize.height);
    CGContextDrawImage(ctx, CGRectMake(0.0, 0.0, imageSize.width, imageSize.height), image.CGImage);
    let newImage:UIImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage
}

Answer 5

您可能希望镜像从相机获得的图像，但您最初得到的图像是正确的。用文字拍照进行比较。

Answer 6

为Swift 3更新了一个稍微简单的答案：

var  statusNames = [];
   var hours = [];
   
var example = [{
  "logged": {
    "status": 0,
    "status_name": "Logged",
    "hours": 23 // to the hours array
  },
  "pending": {
    "status": 3,
    "status_name": "Pending",
    "contribution": {
      "hours": 0,
      "count": 0
    },
    "verification": {
      "hours": 6, // to the hours array
      "count": 1
    }
  },
  "denied": {
    "status": 4,
    "status_name": "Denied",
    "contribution": {
      "hours": 0,
      "count": 0
    },
    "verification": {
      "hours": 0, // to the hours array
      "count": 0
    }
  },
  "approved": {
    "status": 2,
    "status_name": "Approved",
    "contribution": {
      "hours": 4.5,
      "count": 1
    },
    "verification": {
      "hours": 0, // to the hours array
      "count": 0
    }
  }
}];


for (var key in example[0]) {
      statusNames.push(key);
			hours.push(example[0][key]["hours"] || example[0][key]["verification"]["hours"] );
     
}
console.log(statusNames);
console.log(hours);

Answer 7

正如其他答案，我遇到了同样的问题。但只是翻转最终图像只是答案的一半，因为UIPickerController在你用前置摄像头拍照时显示的预览图像，它仍然是倒置的（镜像）。

基于互联网的一些代码，我创建了一个Pod来获得这种想要的行为：

https://github.com/lucasecf/LEMirroredImagePicker

安装完成后，您只需要将这两行代码与UIImagePickerController：

一起调用

self.mirrorFrontPicker = [[LEMirroredImagePicker alloc] initWithImagePicker:pickerController];
[self.mirrorFrontPicker mirrorFrontCamera];

就是这样，就像那样。您可以在github链接的README中查看更多信息。

Answer 8

我想投票给@Lucas Eduardo，我试图将组件LEImagePickerController集成到我的项目中，如下所示：

- (void)onCamera:(id)sender {
    UIImagePickerController* imagePicker = [[UIImagePickerController alloc] init];
    imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
    imagePicker.cameraDevice = UIImagePickerControllerCameraDeviceFront;
    imagePicker.delegate = self;

    //cover the switch button at the top right corner, I just need user take photo with the front facing camera
    UIView* view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 40, 40)];
    view.center = CGPointMake(CGRectGetWidth(imagePicker.view.bounds) - CGRectGetWidth(view.bounds)/2, CGRectGetHeight(view.bounds)/2);
    view.backgroundColor = [UIColor blackColor];
    [imagePicker.view addSubview:view];

    LEMirroredImagePicker* mirrorFrontPicker = [[LEMirroredImagePicker alloc] initWithImagePicker:imagePicker];
    [mirrorFrontPicker mirrorFrontCamera];

    [self presentViewController:imagePicker animated:YES completion:nil];
}

iPhone - 镜像从前置摄像头拍摄的照片

8 个答案: