GalleryViewController.h

-(void)loadImageWithIndex:(int)index toPage:(int)pageIndex{
    if (pageIndex == 0)
    {
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^
        {
            UIImage *pom = [UIImage imageNamed:[self.imageNameArray objectAtIndex:(NSUInteger) index]];
            
            dispatch_async(dispatch_get_main_queue(), ^
            {
                self.imageViewOne.image = pom;
                
                if (self.imageViewOne.hidden)
                {
                    
                    self.imageViewOne.hidden = NO;

                    [UIView animateWithDuration:0.3 animations:^
                    {
                        self.imageViewOne.alpha = 1;
                    }];
                }
            });
        });
    }
    
    if (pageIndex == 1)
    {
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^
        {
            UIImage *pom = [UIImage imageNamed:[self.imageNameArray objectAtIndex:(NSUInteger) index]];
            
            dispatch_async(dispatch_get_main_queue(), ^
            {
                self.imageViewTwo.image = pom;
                
                if (self.imageViewTwo.hidden)
                {
                    self.imageViewTwo.hidden = NO;

                    [UIView animateWithDuration:0.3 animations:^
                    {
                        self.imageViewTwo.alpha = 1;
                    }];
                }
            });
        });
    }
    
    
    if (pageIndex == 2)
    {
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^
        {
            UIImage *pom = [UIImage imageNamed:[self.imageNameArray objectAtIndex:(NSUInteger) index]];
            
            dispatch_async(dispatch_get_main_queue(), ^
            {
                self.imageViewThree.image = pom;
                
                if (self.imageViewThree.hidden)
                {
                    self.imageViewThree.hidden = NO;

                    [UIView animateWithDuration:0.3 animations:^
                    {
                        self.imageViewThree.alpha = 1;
                    }];
                }
            });
        });
    }
}