Photo App with Slicer - ios

Question

I am trying to create my first App for iOS. I would like to create an App which can load a Photo from Library or create a new one with the camera. Then after when I created a photo or load a picture from my library, i would like that it will go to a filter, for example sepia (like it is used in every tutorial) and that I can change the value right now with a slicer on the screen. I will put my source code here, because I dont know if I am doing it right. This is everything from my ViewController.m file
What should I do now to get it working?
#import "ViewController.h"
#interface ViewController ()
{
CIContext *context;
CIFilter *filter;
CIImage *beginImage;
}
#property (nonatomic, retain) UIDocumentInteractionController *documentController;
#end
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
- (void) viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
NSString *filePath = [[NSBundle mainBundle] pathForResource:#"image" ofType:#"png"];
NSURL *fileNamePath = [NSURL fileURLWithPath:filePath];
CIImage *inputImage = [CIImage imageWithContentsOfURL:fileNamePath];
CIFilter *filter = [CIFilter filterWithName:#"CISepia" keysAndValues:kCIInputImageKey, inputImage, #"inputIntensity", #0.8, nil];
CIImage *outputImage = [filter outputImage];
self.ImageView.image = [UIImage imageWithCIImage:outputImage];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)TakePhoto:(id)sender {
picker = [[UIImagePickerController alloc] init];
picker.delegate = self;
[picker setSourceType:UIImagePickerControllerSourceTypeCamera];
[self presentViewController:picker animated:YES completion:NULL];
}
- (IBAction)ChoosePhoto:(id)sender {
picker = [[UIImagePickerController alloc] init];
picker.delegate = self;
[picker setSourceType:UIImagePickerControllerSourceTypePhotoLibrary];
[self presentViewController:picker animated:YES completion:NULL];
}
-(void)imagePickerController:(nonnull UIImagePickerController *)picker didFinishPickingMediaWithInfo:(nonnull NSDictionary<NSString *,id> *)info {
image = [info objectForKey:#"UIImagePickerControllerOriginalImage"];
[self.ImageView setImage:image];
[self dismissViewControllerAnimated:YES completion:NULL];
}
-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker {
[self dismissViewControllerAnimated:YES completion:NULL];
}
- (IBAction)amountSliderValueChanged:(id)sender
{
float slideValue = _Slider.value;
[filter setValue:#(slideValue)
forKey:#"inputIntensity"];
CIImage *outputImage = [filter outputImage];
CGImageRef cgimg = [context createCGImage:outputImage
fromRect:[outputImage extent]];
UIImage *newImage = [UIImage imageWithCGImage:cgimg];
self.ImageView.image = newImage;
CGImageRelease(cgimg);
}