iOS imageview取色處理

標籤：

-(UIImage *)grayImage:(UIImage *)sourceImage {      int bitmapInfo = kCGImageAlphaNone;      int width = sourceImage.size.width;      int height = sourceImage.size.height;      CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();      CGContextRef context = CGBitmapContextCreate ( nil ,                                                    width,                                                    height,                                                    8,       // bits per component                                                    0,                                                    colorSpace,                                                    bitmapInfo);      CGColorSpaceRelease(colorSpace);      if (context == NULL ) {          return nil ;      }      CGContextDrawImage(context,                         CGRectMake(0, 0, width, height), sourceImage.CGImage);      UIImage *grayImage = [UIImage imageWithCGImage:CGBitmapContextCreateImage(context)];      CGContextRelease(context);      return grayImage; }

iOS imageview取色處理