This UIImage category adds one class method that enables you to resize an image, in case you have an asset that is too large.

UIImage+ResizeImage.h

#import <UIKit/UIKit.h>

@interface UIImage (ResizeImage)

+ (UIImage *)convertImage:(UIImage *)image toSize:(CGSize)size;

@end

UIImage+ResizeImage.m

#import "UIImage+ResizeImage.h"

@implementation UIImage (ResizeImage)

+ (UIImage *)convertImage:(UIImage *)image toSize:(CGSize)size
{
    UIGraphicsBeginImageContext(size);
    [image drawInRect:CGRectMake(0.0f, 0.0f, size.width, size.height)];
    UIImage *resizedImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return resizedImage;
}

@end