关闭从画布渲染的黑白位图的抗锯齿功能

发布于 2024-11-17 21:05:28 字数 1885 浏览 4 评论 0原文

我对 WPF 的文本抗锯齿有疑问。在我的应用程序中，用户设计要使用特殊打印设备打印的文本或图像字段。我使用画布来托管字段，这些字段可以是文本块或图像。

问题是当我将此画布转换为 RenderTargetBitmap，然后转换为黑白 FormatConvertedBitmap 时，文本和图像最终看起来非常模糊。

我尝试在应用程序中的所有内容上使用“snaptodevicepixels = true”和“RenderOptions.EdgeMode”= Aliased。我知道抗锯齿对于屏幕来说非常有用，但打印却是一场真正的灾难。

这是我的代码示例：

private BitmapSource GetCanvasAsBitmap(Canvas cvs)
  {   
   cvs.Background = Brushes.White;
   RenderOptions.SetEdgeMode(cvs, EdgeMode.Aliased);
   cvs.SnapsToDevicePixels = true;

   // render TopCanvas visual tree to the RenderTargetBitmap

   Size CanvasSize = new Size(cvs.Width, cvs.Height);
   cvs.Measure(CanvasSize);
   Rect CanvasRect = new Rect(CanvasSize);
   cvs.Arrange(CanvasRect);

   RenderTargetBitmap targetBitmap =
    new RenderTargetBitmap((int)cvs.ActualWidth,
     (int)cvs.ActualHeight,
     96, 96,
     PixelFormats.Default);

   targetBitmap.Render(cvs);


   double scale = PIXELSCALE / cvs.Height;
   ScaleTransform ST = new ScaleTransform(scale, scale);

   TransformedBitmap TB = new TransformedBitmap(targetBitmap, ST);

   return TB;
  }



  private static FormatConvertedBitmap Recolor(BitmapSource b)
  {   
   BmpBitmapEncoder encoder = new BmpBitmapEncoder();
   encoder.Frames.Add(BitmapFrame.Create(b));

   using (FileStream fs = new FileStream("BeforeRecolor.bmp", FileMode.Create))
   {
    encoder.Save(fs);    
    fs.Flush();
    fs.Close();
   }

   FormatConvertedBitmap FCB = new FormatConvertedBitmap(b, PixelFormats.Indexed1, new BitmapPalette(new List<Color>() { Colors.Black, Colors.White }), 0);

   BmpBitmapEncoder en = new BmpBitmapEncoder();
   en.Frames.Add(BitmapFrame.Create(FCB));

   using (FileStream fs = new FileStream("AfterRecolor.bmp", FileMode.Create))
   {
    en.Save(fs);
    fs.Flush();
    fs.Close();
   }

   return FCB;
  }

如何在创建 rendertargetbitmap 之前关闭抗锯齿功能？

原文

I have a problem with WPF's anti aliasing of text. In my application the user designs text or image fields to be printed using a special printing device. I am using a canvas to host the fields, which are either textblocks or Images

The problem is when i convert this canvas into a RenderTargetBitmap, then into a black and white FormatConvertedBitmap, the text and images end up extremely fuzzy looking.

I have tried using "snaptodevicepixels = true" and "RenderOptions.EdgeMode" = Aliased on everything in the application. I know anti aliasing is great for the screen, but printing is a real disaster.

Here is an example of my code:

private BitmapSource GetCanvasAsBitmap(Canvas cvs)
  {   
   cvs.Background = Brushes.White;
   RenderOptions.SetEdgeMode(cvs, EdgeMode.Aliased);
   cvs.SnapsToDevicePixels = true;

   // render TopCanvas visual tree to the RenderTargetBitmap

   Size CanvasSize = new Size(cvs.Width, cvs.Height);
   cvs.Measure(CanvasSize);
   Rect CanvasRect = new Rect(CanvasSize);
   cvs.Arrange(CanvasRect);

   RenderTargetBitmap targetBitmap =
    new RenderTargetBitmap((int)cvs.ActualWidth,
     (int)cvs.ActualHeight,
     96, 96,
     PixelFormats.Default);

   targetBitmap.Render(cvs);


   double scale = PIXELSCALE / cvs.Height;
   ScaleTransform ST = new ScaleTransform(scale, scale);

   TransformedBitmap TB = new TransformedBitmap(targetBitmap, ST);

   return TB;
  }



  private static FormatConvertedBitmap Recolor(BitmapSource b)
  {   
   BmpBitmapEncoder encoder = new BmpBitmapEncoder();
   encoder.Frames.Add(BitmapFrame.Create(b));

   using (FileStream fs = new FileStream("BeforeRecolor.bmp", FileMode.Create))
   {
    encoder.Save(fs);    
    fs.Flush();
    fs.Close();
   }

   FormatConvertedBitmap FCB = new FormatConvertedBitmap(b, PixelFormats.Indexed1, new BitmapPalette(new List<Color>() { Colors.Black, Colors.White }), 0);

   BmpBitmapEncoder en = new BmpBitmapEncoder();
   en.Frames.Add(BitmapFrame.Create(FCB));

   using (FileStream fs = new FileStream("AfterRecolor.bmp", FileMode.Create))
   {
    en.Save(fs);
    fs.Flush();
    fs.Close();
   }

   return FCB;
  }

how do i turn off the antiailasing before creating the rendertargetbitmap?

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哽咽笑 2024-11-24 21:05:28

http://blogs. msdn.com/b/dwayneneed/archive/2008/06/20/implementing-a-custom-bitmapsource.aspx

显然抖动类型是硬编码的

格式转换位图
此类包装了标准 WIC 像素格式
转换器（IWICImagingFactory::CreateFormatConverter）。该组件
提供从一种像素格式转换为另一种像素格式的方法，
处理索引格式、调色板的抖动和半色调
翻译和阿尔法阈值。源、目标格式、
DestinationPalette 和 AlphaThreshold 属性用于
通过初始化底层组件
IWICFormatConverter::初始化。抖动类型被硬编码为
WICBitmapDitherTypeErrorDiffusion。调色板转换类型为
硬编码为 WICBitmapPaletteTypeMedianCut。 ISupport初始化
接口用于捕捉属性的值
初始化完成。属性的进一步更改是
被忽略。