Iteratively optimize and compress UIImage and Convert to Base64 for Server Upload (Objective C).

OptimizeAndEncodeUIImage.m

/* Created by Hersh Bhargava of H2 Micro (www.h2micro.com) */

- (NSString *)compressAndEncodeToBase64String:(UIImage *)image
{
    //Scale Image to some width (xFinal)
    float ratio = image.size.width/image.size.height;
    float xFinal = 700; //Desired image width
    float yFinal = xFinal/ratio;
    UIImage *scaledImage = [self imageWithImage:image scaledToSize:CGSizeMake(xFinal, yFinal)];

    //Compress the image iteratively until either the maximum compression threshold (maxCompression) is reached or the maximum file size requirement is satisfied (maxSize)
    CGFloat compression = 1.0f;
    CGFloat maxCompression = 0.1f;
   	float maxSize = 100*1024; //specified in bytes

    NSData *imageData = UIImageJPEGRepresentation(scaledImage, compression);
    while ([imageData length] > maxSize && compression > maxCompression) {
        compression -= 0.10;
        imageData = UIImageJPEGRepresentation(scaledImage, compression);
        NSLog(@"Compressed to: %.2f MB with Factor: %.2f",(float)imageData.length/1024.0f/1024.0f, compression);
    }
    NSLog(@"Final Image Size: %.2f MB",(float)imageData.length/1024.0f/1024.0f);
    NSString *compressedImageString = [imageData base64EncodedStringWithOptions:NSDataBase64Encoding76CharacterLineLength]; //Alter options as needed.
    return compressedImageString;
}
//This method will decode the base64 string from the above method back into an image.
- (UIImage *)decodeBase64ToImage:(NSString *)strEncodeData
{
    NSData *data = [[NSData alloc]initWithBase64EncodedString:strEncodeData options:NSDataBase64DecodingIgnoreUnknownCharacters];
    UIImage *final = [UIImage imageWithData:data];
    
    return final;
}
//Ancillary method to scale an image based on a CGSize
- (UIImage *)imageWithImage:(UIImage*)originalImage scaledToSize:(CGSize)newSize;
{
    @synchronized(self)
    {
        UIGraphicsBeginImageContext(newSize);
        [originalImage drawInRect:CGRectMake(0,0,newSize.width, newSize.height)];
        UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        return newImage;
    }
    return nil;
}