The difference between captureImage.image; and [captureImage].image; - ios

Question

I am trying to use captureImage.image; in my code however can someone explain what this code will mean and which is correct captureImage.image; or [captureImage].image;
or [captureImage.image];
I am using it for this code
For .h
IBOutlet UIPickerView *SaveTopicker;
NSMutableArray *arraygenre;
}
#property(nonatomic, retain) AVCaptureStillImageOutput *stillImageOutput;
#property (weak, nonatomic) IBOutlet UILabel *categoryLabel;
#property (weak, nonatomic) IBOutlet UIView *imagePreview;
#property (weak, nonatomic) IBOutlet UIView *saveImage;
#property (weak, nonatomic) IBOutlet UIImageView *captureImage;
#property (weak, nonatomic) IBOutlet UISegmentedControl *cameraSwitch;
#property (weak, nonatomic) IBOutlet UIView *pickerViewContainer;
#property (nonatomic, retain) UIAccelerometer *accelerometer;
#property (weak,nonatomic) IBOutlet UIScrollView *BGScrollView;
- (IBAction)saveButton:(id)sender;
- (IBAction)closeButton:(id)sender;
- (IBAction)switchCamera:(id)sender;
- (IBAction)snapImage:(id)sender;
For implementation file
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
//fetch Category Name from the array used to fill the Picker View
NSString *categoryName= [arraygenre objectAtIndex:row];
NSString *fPath = [documentsDirectory stringByAppendingPathComponent:categoryName];
NSFileManager *fileManager=[[NSFileManager alloc]init];
[fileManager createDirectoryAtPath:fPath withIntermediateDirectories:YES attributes:nil error:nil];
[captureImage.image];
[data writeToFile:fPath atomically:YES];
NSData *data= UIImagePNGRepresentation(image);
}
- (IBAction)snapImage:(id)sender {
if (!haveImage) {
captureImage.image = nil; //remove old image from view
captureImage.hidden = NO; //show the captured image view
imagePreview.hidden = YES; //hide the live video feed
[self capImage];
}
else {
captureImage.hidden = YES;
imagePreview.hidden = NO;
haveImage = NO;
}
}
- (void) capImage { //method to capture image from AVCaptureSession video feed
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in stillImageOutput.connections) {
for (AVCaptureInputPort *port in [connection inputPorts]) {
if ([[port mediaType] isEqual:AVMediaTypeVideo] ) {
videoConnection = connection;
break;
}
}
if (videoConnection) {
break;
}
}
NSLog(#"about to request a capture from: %#", stillImageOutput);
[stillImageOutput captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler: ^(CMSampleBufferRef imageSampleBuffer, NSError *error) {
if (imageSampleBuffer != NULL) {
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
[self processImage:[UIImage imageWithData:imageData]];
}
}];
}
- (void) processImage:(UIImage *)image { //process captured image, crop, resize and rotate
haveImage = YES;
if([UIDevice currentDevice].userInterfaceIdiom==UIUserInterfaceIdiomPad) { //Device is ipad
// Resize image
UIGraphicsBeginImageContext(CGSizeMake(768, 1022));
[image drawInRect: CGRectMake(0, 0, 768, 1022)];
UIImage *smallImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGRect cropRect = CGRectMake(0, 130, 768, 768);
CGImageRef imageRef = CGImageCreateWithImageInRect([smallImage CGImage], cropRect);
//or use the UIImage wherever you like
[captureImage setImage:[UIImage imageWithCGImage:imageRef]];
CGImageRelease(imageRef);
captureImage.hidden = NO;
}else{ //Device is iphone
// Resize image
UIGraphicsBeginImageContext(CGSizeMake(320, 426));
[image drawInRect: CGRectMake(0, 0, 320, 426)];
UIImage *smallImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGRect cropRect = CGRectMake(0, 55, 320, 320);
CGImageRef imageRef = CGImageCreateWithImageInRect([smallImage CGImage], cropRect);
[captureImage setImage:[UIImage imageWithCGImage:imageRef]];
CGImageRelease(imageRef);
}
//adjust image orientation based on device orientation
if ([[UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeLeft) {
NSLog(#"landscape left image");
[UIView beginAnimations:#"rotate" context:nil];
[UIView setAnimationDuration:0.5];
captureImage.transform = CGAffineTransformMakeRotation(DegreesToRadians(-90));
[UIView commitAnimations];
}
if ([[UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeRight) {
NSLog(#"landscape right");
[UIView beginAnimations:#"rotate" context:nil];
[UIView setAnimationDuration:0.5];
captureImage.transform = CGAffineTransformMakeRotation(DegreesToRadians(90));
[UIView commitAnimations];
}
if ([[UIDevice currentDevice] orientation] == UIDeviceOrientationPortraitUpsideDown) {
NSLog(#"upside down");
[UIView beginAnimations:#"rotate" context:nil];
[UIView setAnimationDuration:0.5];
captureImage.transform = CGAffineTransformMakeRotation(DegreesToRadians(180));
[UIView commitAnimations];
}
if ([[UIDevice currentDevice] orientation] == UIDeviceOrientationPortrait) {
NSLog(#"upside upright");
[UIView beginAnimations:#"rotate" context:nil];
[UIView setAnimationDuration:0.5];
captureImage.transform = CGAffineTransformMakeRotation(DegreesToRadians(0));
[UIView commitAnimations];
}
}
However I am getting errors saying expected identifier on the first captureImage.image code
and use of undeclared identifier data on the[data writeToFile:fPath atomically:YES];and use of undeclared identifier image in the NSData *data= UIImagePNGRepresentation(image);
Did I do something wrong?

Answer 1

You could probably give some more information on what you're trying to achieve, and what isn't working. To answer your question: captureImage.image is the only one with valid syntax of the three
EDIT: I see you've updated you answer with some code, but it's not clear to me what the captureImage line should do.
captureImage.image calls the image method (usually a property) on the captureImage object, but there's no declaration for that object.
EDIT 2:
Assuming captureImage exists outside of this method, your last few lines should probably be something like this:
UIImage *image = captureImage.image;
NSData *data = UIImagePNGRepresentation(image);
[data writeToFile:fPath atomically:YES];