iPhone - UIImagePickerController -> save the image to app folder - iphone

Question

I have an iPhone application using a UIImagePickerController. As sourceType I have
UIImagePickerControllerSourceTypePhotoLibrary
UIImagePickerControllerSourceTypeCamera
UIImagePickerControllerSourceTypeSavedPhotosAlbum
so the user can make a photo or select one from the photo library from the photos or camera photos.
The image will be displayed in a UIImageView. The image should be saved if the user closes the app. So for text fields, I use NSUserDefaults. I know, it is not a good way to save the image inside the NSUSerDefaults with NSData, so I want to save / copy the image to a folder which is controlled by my application similar to the NSUserDefaults.
How can I do this? I want to save it, and then I can write the path to the file into my NSUserDefaults and read it on startup of the application.
Thank you in advance & Best Regards.

Answer 1

You can use the following code in UIImagePickerControllerDelegate delegate implementation
- (void) imagePickerController:(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary *)info {
//obtaining saving path
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *imagePath = [documentsDirectory stringByAppendingPathComponent:#"latest_photo.png"];
//extracting image from the picker and saving it
NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType];
if ([mediaType isEqualToString:#"public.image"]){
UIImage *editedImage = [info objectForKey:UIImagePickerControllerEditedImage];
NSData *webData = UIImagePNGRepresentation(editedImage);
[webData writeToFile:imagePath atomically:YES];
}
}
UPD
Swift 3.0 code by XueYu
here the image is saved as jpeg but you can also save it as png. the
0.0 parameter stands for compression and it's the lowest quality, if you want to get the best use 1.0.
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
//obtaining saving path
let fileManager = FileManager.default
let documentsPath = fileManager.urls(for: .documentDirectory, in: .userDomainMask).first
let imagePath = documentsPath?.appendingPathComponent("image.jpg")
// extract image from the picker and save it
if let pickedImage = info[UIImagePickerControllerOriginalImage] as? UIImage {
try! UIImageJPEGRepresentation(pickedImage, 0.0)?.write(to: imagePath!)
}
self.dismiss(animated: true, completion: nil)
}

Answer 2

Depending on the file format you want to save, you can use
[UIImagePNGRepresentation(image) writeToFile:path atomically:YES];
OR
[UIImageJPEGRepresentation(image) writeToFile:path atomically:YES];

Answer 3

This is the code to save the UIImage into the document directory. You can use this code in didFinishPickingImage delegate method:
// Create paths to output images
NSString *pngPath = [NSHomeDirectory();
stringByAppendingPathComponent:#"Documents/Test.png"];
NSString *jpgPath = [NSHomeDirectory();
stringByAppendingPathComponent:#"Documents/Test.jpg"];
// Write a UIImage to JPEG with minimum compression (best quality)
// The value 'image' must be a UIImage object
// The value '1.0' represents image compression quality as value from 0.0 to 1.0
[UIImageJPEGRepresentation(image, 1.0) writeToFile:jpgPath atomically:YES];
// Write image to PNG
[UIImagePNGRepresentation(image) writeToFile:pngPath atomically:YES];
// Let's check to see if files were successfully written...
// Create file manager
NSError *error;
NSFileManager *fileMgr = [NSFileManager defaultManager];
// Point to Document directory
NSString *documentsDirectory = [NSHomeDirectory();
stringByAppendingPathComponent:#"Documents"];
// Write out the contents of home directory to console
NSLog(#"Documents directory: %#", [fileMgr contentsOfDirectoryAtPath:documentsDirectory error:&error]);
EDIT
You can also use:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
to find the path to your application document directory, instead of NSHomeDierctory.

Answer 4

Update knuku's answer for Swift 3.0
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
//obtaining saving path
let fileManager = FileManager.default
let documentsPath = fileManager.urls(for: .documentDirectory, in: .userDomainMask).first
let imagePath = documentsPath?.appendingPathComponent("image.jpg")
// extract image from the picker and save it
if let pickedImage = info[UIImagePickerControllerOriginalImage] as? UIImage {
try! UIImageJPEGRepresentation(pickedImage, 0.0)?.write(to: imagePath!)
}
self.dismiss(animated: true, completion: nil)
}
here the image is saved as jpeg but you can also save it as png. the 0.0 parameter stands for compression and it's the lowest quality, if you want to get the best use 1.0.