MonoTouch将颜色UIImage转换为alpha到灰度和模糊？

Question

我试图找到一个UIImage从PNG和alpha颜色生成模糊灰度的配方.ObjC中有配方,但MonoTouch不绑定CGRect功能,所以不知道如何做到这一点.有任何想法吗？

这是灰度的一个ObjC示例:

(UIImage *)convertImageToGrayScale:(UIImage *)image
{
  // Create image rectangle with current image width/height
  CGRect imageRect = CGRectMake(0, 0, image.size.width, image.size.height);

  // Grayscale color space
  CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();

  // Create bitmap content with current image size and grayscale colorspace
  CGContextRef context = CGBitmapContextCreate(nil, image.size.width, image.size.height, 8, 0,   colorSpace, kCGImageAlphaNone);

  // Draw image into current context, with specified rectangle
  // using previously defined context (with grayscale colorspace)
  CGContextDrawImage(context, imageRect, [image CGImage]);

  // Create bitmap image info from pixel data in current context
  CGImageRef imageRef = CGBitmapContextCreateImage(context);

  // Create a new UIImage object  
  UIImage *newImage = [UIImage imageWithCGImage:imageRef];

  // Release colorspace, context and bitmap information
  CGColorSpaceRelease(colorSpace);
  CGContextRelease(context);
  CFRelease(imageRef);

  // Return the new grayscale image
  return newImage;
}

Answer 1

Monotouch不绑定CGRect功能,因此不确定如何执行此操作.

使用MonoTouch时CGRect映射到RectangleF.存在许多应该映射到每个函数的扩展方法GCRect.使用它们移植ObjectiveC代码应该没有任何问题.

如果缺少某些内容,请填写错误报告@ http://bugzilla.xamarin.com,我们将尽快修复它(并在可能的情况下提供解决方法).

ObjC中有配方,但有MonoTouch

如果您有链接,请编辑您的问题并添加它们.这将使你更容易帮助你:)

UPDATE

这是您的示例的逐行C#转换.它似乎对我有用(而且我的眼睛比Objective-C更容易;-)

    UIImage ConvertToGrayScale (UIImage image)
    {
        RectangleF imageRect = new RectangleF (PointF.Empty, image.Size);
        using (var colorSpace = CGColorSpace.CreateDeviceGray ())
        using (var context = new CGBitmapContext (IntPtr.Zero, (int) imageRect.Width, (int) imageRect.Height, 8, 0, colorSpace, CGImageAlphaInfo.None)) {
            context.DrawImage (imageRect, image.CGImage);
            using (var imageRef = context.ToImage ())
                return new UIImage (imageRef);
        }
    }