xcode5: how can I save and load an image? - ios

Question

I'm developing an app, where I can apply filters on an image. I want to create an undo button which resets the original image in the imageView.
The solution is that I just save the original image in it's own UIImage object before I apply any filters to it. This way I can just go back to that in my undo method.
Does somebody know how I can do this?

Answer 1

Take a look at the docs here: https://developer.apple.com/library/ios/documentation/uikit/reference/UIKitFunctionReference/Reference/reference.html
You can do what you want with UIImagePNGRepresentation().
Then to re-read: imageWithContentsOfFile:

Answer 2

Get Image from disk . Suppose image stored in document directory.
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *yourImgPath = [documentsDirectory stringByAppendingPathComponent:#"1.png"];
UIImage *originalImage = [UIImage imageWithContentsOfFile:yourImgPath];
Create tempImage from originalImage
UIImage *tempImage = originalImage;
Appy filters on tempImage
EDIT : How to save then below is method to save in document directory.
- (BOOL)saveImageInDocDir:(UIImage *)image withImagename:(NSString *)strImgName {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *savedImagePath = [documentsDirectory stringByAppendingPathComponent:strImgName];
NSData *imageData = UIImagePNGRepresentation(image);
BOOL isSaved = [imageData writeToFile:savedImagePath atomically:YES];
return isSaved;
}
You can also use NSTempraryDirectory to save images as its safe from cloud backup