The UIImage doesn’t implement the NSCoder protocol directly that is necessary for storage in plists.

But, it is fairly easy to add like below.

UIImage+NSCoder.h

#import <Foundation/Foundation.h>

@interface UIImage (MyExtensions)
- (void)encodeWithCoder:(NSCoder *)encoder;
- (id)initWithCoder:(NSCoder *)decoder;
@end

UIImage+NSCoder.m

#import "UIImage+NSCoder.h"

@implementation UIImage (MyExtensions)

- (void)encodeWithCoder:(NSCoder *)encoder
{
  [encoder encodeDataObject:UIImagePNGRepresentation(self)];
}

- (id)initWithCoder:(NSCoder *)decoder
{
  return [self initWithData:[decoder decodeDataObject]];
}

@end

When this has been added you will be able to store UIImages in plist with ie

// Get a full path to a plist within the Documents folder for the app
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
                                                     NSUserDomainMask,
                                                     YES);
NSString *path = [NSString stringWithFormat:@"%@/my.plist",
                                              [paths objectAtIndex:0]];

// Place an image in a dictionary that will be stored as a plist
[dictionary setObject:image forKey:@"image"];

// Write the dictionary to the filesystem as a plist
[NSKeyedArchiver archiveRootObject:dictionary toFile:path];

Note: I do not recommend doing this, unless you really want to, ie for really small images.