问题
Is it even possible to enable the HDR option from within my application? I assumed it would be there automatically. I looked for additional mediaTypes, thinking maybe kUTTypeHDRImage might be an option, but no such luck. It's not an additional source type, nor is it available through cameraCaptureMode.
ipc.sourceType = UIImagePickerControllerSourceTypeCamera;
ipc.mediaTypes = [NSArray arrayWithObject:(NSString *)kUTTypeImage];No mention of it in the documentation: http://developer.apple.com/library/ios/#documentation/uikit/reference/UIImagePickerController_Class/UIImagePickerController/UIImagePickerController.html
回答1:
The HDR option is specific to the Camera app and is not available through the API.
You should file an enhancement request at http://bugreport.apple.com.
回答2:
It's not a separate media type; it's still an image, and (to my knowledge) still a JPEG. I think what Camera is doing is taking multiple images at different exposure levels and combining them together; that's why it takes so long.
来源：https://stackoverflow.com/questions/3814692/enable-hdr-option-for-uiimagepickercontroller