Raw image data from camera - iphone

Question

I've been searching this forum up and down but I couldn't find what I really need. I want to get raw image data from the camera. Up till now I tried to get the data out of the imageDataSampleBuffer from that method captureStillImageAsynchronouslyFromConnection:completionHandler: and to write it to an NSData object, but that didn't work.
Maybe I'm on the wrong track or maybe I'm just doing it wrong.
What I don't want is for the image to be compressed in any way.
The easy way is to use jpegStillImageNSDataRepresentation: from AVCaptureStillImageOutput, but like I said I don't want it to be compressed.
Thanks!

Answer 1

This is how i do it:
1: I first open the camera using:
- (void)openCamera
{
imagePicker = [[UIImagePickerController alloc] init];
imagePicker.delegate = self;
if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
{
imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
imagePicker.mediaTypes = [NSArray arrayWithObjects:
(NSString *) kUTTypeImage,
(NSString *) kUTTypeMovie, nil];
imagePicker.allowsEditing = NO;
[self presentModalViewController:imagePicker animated:YES];
}
else {
lblError.text = NSLocalizedStringFromTable(#"noCameraFound", #"Errors", #"");
}
}
When the picture is taken this method gets called:
-(void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
// Save and get the path of the image
NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType];
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
if([mediaType isEqualToString:(NSString *)kUTTypeImage])
{
// Save the image
image = [info objectForKey:#"UIImagePickerControllerOriginalImage"];
[library writeImageToSavedPhotosAlbum:[image CGImage] orientation:(ALAssetOrientation)[image imageOrientation] completionBlock:^(NSURL *assetURL, NSError *error){
if(!error) {
//Save path and location to database
NSString *pathLocation = [[NSString alloc] initWithFormat:#"%#", assetURL];
} else {
NSLog(#"CameraViewController: Error on saving image : %# {imagePickerController}", error);
}
}];
}
[imagePicker dismissModalViewControllerAnimated:YES];
}
Then with that path i get the picture from the library in FULL resolution (using the "1"):
-(void)preparePicture: (NSString *) filePathPicture{
ALAssetsLibraryAssetForURLResultBlock resultBlock = ^(ALAsset *myasset)
{
if(myasset != nil){
ALAssetRepresentation *assetRep = [myasset defaultRepresentation];
CGImageRef imageRef = [assetRep fullResolutionImage];
if (imageRef) {
NSData *imageData = UIImageJPEGRepresentation([UIImage imageWithCGImage:imageRef], 1);
}
}else {
//error
}
};
ALAssetsLibraryAccessFailureBlock failureBlock = ^(NSError *error)
{
NSString *errorString = [NSString stringWithFormat:#"can't get image, %#",[error localizedDescription]];
NSLog(#"%#", errorString);
};
if(filePathPicture && [filePathPicture length])
{
NSURL *assetUrl = [NSURL URLWithString:filePathPicture];
ALAssetsLibrary *assetslibrary = [[ALAssetsLibrary alloc] init];
[assetslibrary assetForURL:assetUrl
resultBlock:resultBlock
failureBlock:failureBlock];
}
}
Hope this helps you a bit further :-).