CGImageCreateWithImageInRect Holding Onto Image Data - Leaking? - ios

Question

I am trying to take an image snapshot, crop it, and save it to a UIImageView.
I have tried this from a few dozen different directions but here is the general setup.
First, I am running this under ARC, XCODE 7.2, testing on a 6Plus phone iOS 9.2.
Here is now the delegate is setup..
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
NSLog(#"CameraViewController : imagePickerController");
//Get the Image Data
NSData *getDataImage = UIImageJPEGRepresentation([info objectForKey:#"UIImagePickerControllerOriginalImage"], 0.9);
// Turn it into a UI image
UIImage *getCapturedImage = [[UIImage alloc] initWithData:getDataImage];
// Figure out the size and build the rectangle we are going to put the image into
CGSize imageSize = getCapturedImage.size;
CGFloat imageScale = getCapturedImage.scale;
int yCoord = (imageSize.height - ((imageSize.width*2)/3))/2;
CGRect getRect = CGRectMake(0, yCoord, imageSize.width, ((imageSize.width*2)/3));
CGRect rect = CGRectMake(getRect.origin.x*imageScale,
getRect.origin.y*imageScale,
getRect.size.width*imageScale,
getRect.size.height*imageScale);
//Resize the image and store it
CGImageRef imageRef = CGImageCreateWithImageInRect([getCapturedImage CGImage], rect);
//Stick the resulting image into an image variable
UIImage *cropped = [UIImage imageWithCGImage:imageRef];
//Release that reference
CGImageRelease(imageRef);
//Save the newly cropped image to a UIImageView property
_imageView.image = cropped;
_saveBtn.hidden = NO;
[picker dismissViewControllerAnimated:YES completion:^{
// After we are finished with dismissing the picker, run the below to close out the camera tool
[self dismissCameraViewFromImageSelect];
}];
}
When I run the above I get the below image.
At this point I am viewing the image in the previously set _imageView.image. And the image data has gobbled up 30MB. But when I back out of this view, the image data is still retained.
If I try to go through the process of capturing a new image this is what I get.
And when I bypass resizing the image and assign it to the ImageView there is no 30MB gobbled.
I have looked at all the advice on this and everything suggested doesn't make a dent but lets go over what I tried and didn't work.
Did not work.
Putting it in a #autoreleasepool block.
This never seems to work. Maybe I am not doing it right but having tried this a few different ways, nothing released the memory.
CGImageRelease(imageRef);
I am doing that but I have tried this a number of different ways. Still no luck.
CFRelease(imageRef);
Also doesn't work.
Setting imageRef = nil;
Still retains. Even the combination of that and CGImageRelease didn't work for me.
I have tried separating the cropping aspect into its own function and returning the results but still no luck.
I haven't found anything particularly helpful online and all references to similar issues have advice (as mentioned above) that doesn't seem to work.
Thanks for your advice in advance.

Answer 1

Alright, after much time thinking on this, I decided to just start from scratch and since most of my recent work has been in Swift, I put together a swift class that can be called, controls the camera, and passes up the image through a delegate to the caller.
The end result is that I don't have this memory leak where some variable is holding on to the memory of the previous image and I can use it in my current project by bridging the Swift class file to my Obj-C ViewControllers.
Here is the Code for the class that does the fetching.
//
// CameraOverlay.swift
// CameraTesting
//
// Created by Chris Cantley on 3/3/16.
// Copyright © 2016 Chris Cantley. All rights reserved.
//
import Foundation
import UIKit
import AVFoundation
//We want to pass an image up to the parent class once the image has been taken so the easiest way to send it up
// and trigger the placing of the image is through a delegate.
protocol CameraOverlayDelegate: class {
func cameraOverlayImage(image:UIImage)
}
class CameraOverlay: NSObject, AVCaptureVideoDataOutputSampleBufferDelegate {
//MARK: Internal Variables
//Setting up the delegate reference to be used later on.
internal var delegate: CameraOverlayDelegate?
//Varibles for setting the camera view
internal var returnImage : UIImage!
internal var previewView : UIView!
internal var boxView:UIView!
internal let myButton: UIButton = UIButton()
//Setting up Camera Capture required properties
internal var previewLayer:AVCaptureVideoPreviewLayer!
internal var captureDevice : AVCaptureDevice!
internal let session=AVCaptureSession()
internal var stillImageOutput: AVCaptureStillImageOutput!
//When we put up the camera preview and the button we have to reference a parent view so this will hold the
// parent view passed into the class so that other methods can work with it.
internal var view : UIView!
//When this class is instantiated, we want to require that the calling class passes us
//some view that we can tie the camera previewer and button to.
//MARK: - Instantiation Methods
init(parentView: UIView){
//Instantiate the reference to the passed-in UIView
self.view = parentView
//We are doing the following here because this only needs to be setup once per instantiation.
//Create the output container with settings to specify that we are getting a still Image, and that it is a JPEG.
stillImageOutput = AVCaptureStillImageOutput()
stillImageOutput.outputSettings = [AVVideoCodecKey: AVVideoCodecJPEG]
//Now we are sticking the image into the above formatted container
session.addOutput(stillImageOutput)
}
//MARK: - Public Functions
func showCameraView() {
//This handles showing the camera previewer and button
self.setupCameraView()
//This sets up the parameters for the camera and begins the camera session.
self.setupAVCapture()
}
//MARK: - Internal Functions
//When the user clicks the button, this gets the image, sends it up to the delegate, and shuts down all the Camera related views.
internal func didPressTakePhoto(sender: UIButton) {
//Create a media connection...
if let videoConnection = stillImageOutput!.connectionWithMediaType(AVMediaTypeVideo) {
//Setup the orientation to be locked to portrait
videoConnection.videoOrientation = AVCaptureVideoOrientation.Portrait
//capture the still image from the camera
stillImageOutput?.captureStillImageAsynchronouslyFromConnection(videoConnection, completionHandler: {(sampleBuffer, error) in
if (sampleBuffer != nil) {
//Get the image data
let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(sampleBuffer)
let dataProvider = CGDataProviderCreateWithCFData(imageData)
let cgImageRef = CGImageCreateWithJPEGDataProvider(dataProvider, nil, true, CGColorRenderingIntent.RenderingIntentDefault)
//The 2.0 scale halves the scale of the image. Where as the 1.0 gives you the full size.
let image = UIImage(CGImage: cgImageRef!, scale: 2.0, orientation: UIImageOrientation.Up)
// What size is this image.
let imageSize = image.size
let imageScale = image.scale
let yCoord = (imageSize.height - ((imageSize.width*2)/3))/2
let getRect = CGRectMake(0, yCoord, imageSize.width, ((imageSize.width*2)/3))
let rect = CGRectMake(getRect.origin.x*imageScale, getRect.origin.y*imageScale, getRect.size.width*imageScale, getRect.size.height*imageScale)
let imageRef = CGImageCreateWithImageInRect(image.CGImage, rect)
//let newImage = UIImage(CGImage: imageRef!)
//This app forces the user to use landscapto take pictures so this simply turns the image so that it looks correct when we take the image.
let newImage: UIImage = UIImage(CGImage: imageRef!, scale: image.scale, orientation: UIImageOrientation.Down)
//Pass the image up to the delegate.
self.delegate?.cameraOverlayImage(newImage)
//stop the session
self.session.stopRunning()
//Remove the views.
self.previewView.removeFromSuperview()
self.boxView.removeFromSuperview()
self.myButton.removeFromSuperview()
//By this point the image has been handed off to the caller through the delegate and memory has been cleaned up.
}
})
}
}
internal func setupCameraView(){
//Add a view that is big as the frame that acts as a background.
self.boxView = UIView(frame: self.view.frame)
self.boxView.backgroundColor = UIColor(red: 255, green: 255, blue: 255, alpha: 1.0)
self.view.addSubview(self.boxView)
//Add Camera Preview View
// This sets up the previewView to be a 3:2 aspect ratio
let newHeight = UIScreen.mainScreen().bounds.size.width / 2 * 3
self.previewView = UIView(frame: CGRectMake(0, 0, UIScreen.mainScreen().bounds.size.width, newHeight))
self.previewView.backgroundColor = UIColor.cyanColor()
self.previewView.contentMode = UIViewContentMode.ScaleToFill
self.view.addSubview(previewView)
//Add the button.
myButton.frame = CGRectMake(0,0,200,40)
myButton.backgroundColor = UIColor.redColor()
myButton.layer.masksToBounds = true
myButton.setTitle("press me", forState: UIControlState.Normal)
myButton.setTitleColor(UIColor.whiteColor(), forState: UIControlState.Normal)
myButton.layer.cornerRadius = 20.0
myButton.layer.position = CGPoint(x: self.view.frame.width/2, y:(self.view.frame.height - myButton.frame.height ) )
myButton.addTarget(self, action: "didPressTakePhoto:", forControlEvents: .TouchUpInside)
self.view.addSubview(myButton)
}
internal func setupAVCapture(){
session.sessionPreset = AVCaptureSessionPresetPhoto;
let devices = AVCaptureDevice.devices();
// Loop through all the capture devices on this phone
for device in devices {
// Make sure this particular device supports video
if (device.hasMediaType(AVMediaTypeVideo)) {
// Finally check the position and confirm we've got the front camera
if(device.position == AVCaptureDevicePosition.Back) {
captureDevice = device as? AVCaptureDevice
if captureDevice != nil {
//-> Now that we have the back of the camera, start a session.
beginSession()
break;
}
}
}
}
}
// Sets up the session
internal func beginSession(){
var err : NSError? = nil
var deviceInput:AVCaptureDeviceInput?
//See if we can get input from the Capture device as defined in setupAVCapture()
do {
deviceInput = try AVCaptureDeviceInput(device: captureDevice)
} catch let error as NSError {
err = error
deviceInput = nil
}
if err != nil {
print("error: \(err?.localizedDescription)")
}
//If we can add input into the AVCaptureSession() then do so.
if self.session.canAddInput(deviceInput){
self.session.addInput(deviceInput)
}
//Now show layers that were setup in the previewView, and mask it to the boundary of the previewView layer.
let rootLayer :CALayer = self.previewView.layer
rootLayer.masksToBounds=true
//put a live video capture based on the current session.
self.previewLayer = AVCaptureVideoPreviewLayer(session: self.session);
// Determine how to fill the previewLayer. In this case, I want to fill out the space of the previewLayer.
self.previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
self.previewLayer.frame = rootLayer.bounds
//Put the sublayer into the previewLayer
rootLayer.addSublayer(self.previewLayer)
session.startRunning()
}
}
Here is how I am using this class in a view controller.
//
// ViewController.swift
// CameraTesting
//
// Created by Chris Cantley on 2/26/16.
// Copyright © 2016 Chris Cantley. All rights reserved.
//
import UIKit
import AVFoundation
class ViewController: UIViewController, CameraOverlayDelegate{
//Setting up the class reference.
var cameraOverlay : CameraOverlay!
//Connected to the UIViewController main view.
#IBOutlet var getView: UIView!
//Connected to an ImageView that will display the image when it is passed back to the delegate.
#IBOutlet weak var imgShowImage: UIImageView!
//Connected to the button that is pressed to bring up the camera view.
#IBAction func btnPictureTouch(sender: AnyObject) {
//Remove the image from the UIImageView and take another picture.
self.imgShowImage.image = nil
self.cameraOverlay.showCameraView()
}
override func viewDidLoad() {
super.viewDidLoad()
//Pass in the target UIView which in this case is the main view
self.cameraOverlay = CameraOverlay(parentView: getView)
//Make this class the delegate for the instantiated class.
//That way it knows to receive the image when the user takes a picture
self.cameraOverlay.delegate = self
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
//Nothing here but if you run out of memorry you might want to do something here.
}
override func shouldAutorotate() -> Bool {
if (UIDevice.currentDevice().orientation == UIDeviceOrientation.LandscapeLeft ||
UIDevice.currentDevice().orientation == UIDeviceOrientation.LandscapeRight ||
UIDevice.currentDevice().orientation == UIDeviceOrientation.Unknown) {
return false;
}
else {
return true;
}
}
//This references the delegate from CameraOveralDelegate
func cameraOverlayImage(image: UIImage) {
//Put the image passed up from the CameraOverlay class into the UIImageView
self.imgShowImage.image = image
}
}
Here is a link to the project where I put that together.
GitHub - Boiler plate get image from camera