- (UIImage *)imageProcess:(UIImage *)image
{
    CGImageRef inImage = image.CGImage;
    CGContextRef ctx;

    CFDataRef m_DataRef;
    m_DataRef = CGDataProviderCopyData(CGImageGetDataProvider(inImage));
    UInt8 * m_PixelBuf = (UInt8 *) CFDataGetBytePtr(m_DataRef);
    //    Byte tmpByte;
    int length = CFDataGetLength(m_DataRef);
    NSLog(@"len %d", length);

    NSLog(@"width=%d, height=%d", CGImageGetWidth( inImage ), CGImageGetHeight( inImage ));
    NSLog(@"1=%d, 2=%d, 3=%d", CGImageGetBitsPerComponent(inImage), CGImageGetBitsPerPixel(inImage),CGImageGetBytesPerRow(inImage));
    float distance, coefficent;
    int x, y;
    int width = CGImageGetWidth(inImage);
    int height = CGImageGetHeight(inImage);
    int centerx = CGImageGetWidth(inImage)/2;
    int centery = CGImageGetWidth(inImage)/2;
    float maxDist = sqrt(pow(centerx,2)+pow(centery, 2));
    NSLog(@"maxdist: %f", maxDist);

    for (int index = 0; index < length; index += 4)
    {
        x = (index/4) % width+1;
        y = floor((index/4)/width)+1;
        distance = sqrt(pow((x-centerx),2)+pow((y-centery),2));
        coefficent = cos((90*distance * (3.14159265358/180)) / maxDist);
        NSLog(@"coefficent: cos((90* %f * (3.14159265358/180)) / %f)=%f",distance, maxDist, coefficent);
        m_PixelBuf[index + 1] = 255 * coefficent;
        m_PixelBuf[index + 2] = 255 * coefficent;
        m_PixelBuf[index + 3] = 255 * coefficent;
        //m_PixelBuf[index + 1] = m_PixelBuf[index + 1];
        //m_PixelBuf[index + 2] = m_PixelBuf[index + 2];
        //m_PixelBuf[index + 3] = m_PixelBuf[index + 3];

    }
    ctx = CGBitmapContextCreate(m_PixelBuf,
                                CGImageGetWidth( inImage ),
                                CGImageGetHeight( inImage ),
                                8,
                                CGImageGetBytesPerRow( inImage ),
                                CGImageGetColorSpace( inImage ),
                                kCGImageAlphaPremultipliedFirst );

    CGImageRef imageRef = CGBitmapContextCreateImage (ctx);
    UIImage* rawImage = [UIImage imageWithCGImage:imageRef];
    CGContextRelease(ctx);
    return rawImage;
}