UIImagePickerControllerEditedImage 的问题

我需要在将图像导入应用程序之前对其进行编辑，但编辑图像后会降低一些质量，如何避免这种情况？

- (void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {

    [self dismissModalViewControllerAnimated:YES];
    imgEdited.image = [info objectForKey:UIImagePickerControllerEditedImage];


}

您可以裁剪UIImagePickerControllerOriginalImage手动使用通过提供的值UIImagePickerControllerCropRect.

未经测试的快速和肮脏的例子：

static UIImage *my_croppedImage(UIImage *image, CGRect cropRect)
{
    UIGraphicsBeginImageContext(cropRect.size);
    [image drawAtPoint:CGPointMake(-cropRect.origin.x, -cropRect.origin.y)];
    UIImage *cropped = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return cropped;
}

- (void) imagePickerController:(UIImagePickerController *)picker
 didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    // …

    UIImage *originalImage = info[UIImagePickerControllerOriginalImage];
    CGRect cropRect = [info[UIImagePickerControllerCropRect] CGRectValue];
    UIImage *croppedImage = my_croppedImage(originalImage, cropRect);

    // …
}