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如何在显示时裁剪UIImagePickerController拍摄的图片

crop uiimagepickercontroller objective-c ios

9

Adam Bardon · 技术社区 · 13 年前

当我使用UIImagePickerController拍照时,画面比屏幕上看到的要多。。。我怎样才能拍照/裁剪它,使它与我在屏幕上看到的完全一样?

编辑:我将添加代码,以指定我的问题:

- (void)showImagePickerForSourceType:(UIImagePickerControllerSourceType)sourceType
{

UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];
imagePickerController.modalPresentationStyle = UIModalPresentationCurrentContext;
imagePickerController.sourceType = sourceType;
imagePickerController.delegate = self;
imagePickerController.showsCameraControls = NO;
imagePickerController.allowsEditing = YES;

if (sourceType == UIImagePickerControllerSourceTypeCamera)
{
    [[NSBundle mainBundle] loadNibNamed:@"OverlayView" owner:self options:nil];
    self.overlayView.frame = imagePickerController.cameraOverlayView.frame;
    imagePickerController.cameraOverlayView = self.overlayView;
    //self.overlayView = nil;
    self.overlayImage.image = self.imageView.image;
    self.overlayImage.alpha = 0.5;

    UISlider *slider=[[UISlider alloc]initWithFrame:CGRectMake(60, 80, 200, 30)];
    [slider setMaximumValue:1.0];
    [slider setMinimumValue:0.0];
    [slider setValue:0.5];
    [slider addTarget:self action:@selector(sliderChanged:)  forControlEvents:UIControlEventValueChanged];

    if (self.working == TRUE)
    {
        [imagePickerController.cameraOverlayView addSubview:self.overlayImage];
        [imagePickerController.cameraOverlayView addSubview:slider];
    }
}

self.imagePickerController = imagePickerController;
[self presentViewController:self.imagePickerController animated:YES completion:nil];
}

did完成选择带有信息的媒体:

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
[self dismissViewControllerAnimated:YES completion:NULL];

//this works, image is displayed
UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
//this doesn't work, image is nil
UIImage *image = [info objecyForKey:UIImagePickerControllerEditedImage];    

[self.imageView setImage:image];
self.working = TRUE;

self.imagePickerController = nil;
//[self dismissViewControllerAnimated:YES completion:NULL];
}

何时可以使用UIImagePickerControllerEditedImage imagePickerController.showsCameraControls = NO; ?

3 回复 | 直到 13 年前

1

10

Rok Jarc 13 年前

根据信息字典的关键字,您可以获得原始或裁剪的图像。

这个 pickedImageEdited 将是您要查找的裁剪图像 pickedImageOriginal 将是完整的原始图像。

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    UIImage *pickedImageOriginal = [info objectForKey:UIImagePickerControllerOriginalImage];

    UIImage *pickedImageEdited = [info objectForKey:UIImagePickerControllerEditedImage];

    //do your stuff

    [self dismissViewControllerAnimated:YES completion:nil];
}

2

9

Wim Haanstra 13 年前

只是把这个作为答案发布,但我不确定海报是否要求编辑图片。

当您使用UIImagePickerController拍摄照片时,选择器只显示拍摄照片时实际拍摄的图像的一部分,如下图所示,黑线是iPhone的屏幕。

enter image description here

你从相机上得到的图像是全尺寸的图像,但在屏幕上只是图像的中心,图像的宽度或高度都达到了屏幕大小。

你所需要做的就是从上面显示的图像中获取中心,这样你就可以在屏幕上获得准确的图像。

3

5

Adam Bardon 13 年前

在Wim回答后,我想出了这样的解决方案:

UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];

UIGraphicsBeginImageContext(CGSizeMake(720, 960));
[image drawInRect: CGRectMake(0, 0, 720, 960)];
UIImage *smallImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

CGRect cropRect = CGRectMake(40, 0, 640, 960);

CGImageRef imageRef = CGImageCreateWithImageInRect([smallImage CGImage], cropRect);
[self.imageView setImage:[UIImage imageWithCGImage:imageRef]];

正如你所看到的,这是为3.5英寸的iPhone屏幕制作的,它似乎可以工作,但代码取决于设备,或者有更好的解决方案吗?