gistfile1.m

- (UIImage *)imageScaledToSizeKeepingAspectRatioWithWidth:(CGFloat)targetMinimumWidth contextSize:(CGSize)contextSize {
    CGSize originalSize = self.size;
    CGFloat newHeight = (originalSize.height / originalSize.width) * targetMinimumWidth;
    
    UIGraphicsBeginImageContextWithOptions(contextSize, NO, 1);
    [self drawInRect:CGRectMake(0, 0, targetMinimumWidth, newHeight)];
    
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;
}