ios 이미지 픽젤값 변경 질문이빈다.

- (UIImage *)processWithePixels:(UIImage*)teeImage alpha:(int)trans{
    UInt32 * teePixels;
 
    CGImageRef teeCGImage = [teeImage CGImage];
    NSUInteger teeWidth = CGImageGetWidth(teeCGImage);
    NSUInteger teeHeight = CGImageGetHeight(teeCGImage);
 
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
 
    NSUInteger bytesPerPixel = 4;
    NSUInteger bitsPerComponent = 8;
 
    NSUInteger teeBytesPerRow = bytesPerPixel * teeWidth;
 
    teePixels = (UInt32 *)calloc(teeHeight * teeWidth, sizeof(UInt32));
 
 
    CGBitmapInfo bitmapInfo = kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big;
    CGContextRef context =   CGBitmapContextCreate(teePixels, teeWidth, teeHeight,
                                                 bitsPerComponent, teeBytesPerRow, colorSpace,
                                                 bitmapInfo);
    CGContextDrawImage(context, CGRectMake(0, 0, teeWidth, teeHeight), teeCGImage);
 
 
    for (NSUInteger j = 0; j < teeHeight; j++) {
        for (NSUInteger i = 0; i < teeWidth; i++) {
            UInt32 * currentPixel  = teePixels + ( j * teeWidth) + i;
 
            UInt32 color = *currentPixel;
 
            *currentPixel = 0x00FFFFFF;
        }
    }
    // 4. Create a new UIImage
    CGImageRef newCGImage = CGBitmapContextCreateImage(context);
    UIImage * processedImage = [UIImage imageWithCGImage:newCGImage scale:1 orientation:teeImage.imageOrientation];
 
    // 5. Cleanup!
    CGColorSpaceRelease(colorSpace);
 
    CGContextRelease(context);
 
    CFRelease(newCGImage);
    free(teePixels);
 
    return processedImage;
};