C＃轉換圖像來完成黑白

Question

我有一個GIF圖像是太大了我的需求（即使是100〜300KB）

在Photoshop中，我成功地把我的160KB的GIF 15KB（1/10他的大小！）簡單地通過減少他使用2（黑&白）色數。

我想做同樣的事情在我的應用程序，但所有我能找到的轉向圖像爲灰度它把我的160KB的GIF 100KB。

反正把我的GIF爲COMPLETE黑白？任何其他方式，可以縮小GIF到更小的尺寸將不勝感激。

Answer 1

下面是如何把它變成一個黑白G4壓縮的TIFF一個codeproject example。請注意，對於包含大量空白和文本的圖像而言，這非常好，但對圖像不太好。使用圖片時，您可能希望看到其他答案並使用抖動。

Answer 2

查找到弗洛伊德 - 斯坦伯格抖動：http://en.wikipedia.org/wiki/Floyd%E2%80%93Steinberg_dithering

或者，如果你不需要抖動，發現平均亮度，打開上面的所有像素爲白色，低於爲黑色。

Answer 3

這裏有一些代碼對SO：Bayer Ordered Dithering那是應該做的，我認爲（未測試）。值得一試。

Answer 4

Converting Image to Black and White in C#

/* 
Copyright (c) 2010 <a href="http://www.gutgames.com">James Craig</a> 

Permission is hereby granted, free of charge, to any person obtaining a copy 
of this software and associated documentation files (the "Software"), to deal 
in the Software without restriction, including without limitation the rights 
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
copies of the Software, and to permit persons to whom the Software is 
furnished to do so, subject to the following conditions: 

The above copyright notice and this permission notice shall be included in 
all copies or substantial portions of the Software. 

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
THE SOFTWARE.*/ 

#region Usings 
using System.Drawing; 
using System.Drawing.Imaging; 
#endregion 

namespace Utilities.Media.Image 
{ 
    /// <summary> 
    /// Helper class for setting up and applying a color matrix 
    /// </summary> 
    public class ColorMatrix 
    { 
     #region Constructor 

     /// <summary> 
     /// Constructor 
     /// </summary> 
     public ColorMatrix() 
     { 
     } 

     #endregion 

      #region Properties 

     /// <summary> 
     /// Matrix containing the values of the ColorMatrix 
     /// </summary> 
     public float[][] Matrix { get; set; } 

     #endregion 

     #region Public Functions 

     /// <summary> 
     /// Applies the color matrix 
     /// </summary> 
     /// <param name="OriginalImage">Image sent in</param> 
     /// <returns>An image with the color matrix applied</returns> 
     public Bitmap Apply(Bitmap OriginalImage) 
     { 
      using (Graphics NewGraphics = Graphics.FromImage(NewBitmap)) 
      { 
       System.Drawing.Imaging.ColorMatrix NewColorMatrix = new System.Drawing.Imaging.ColorMatrix(Matrix); 
       using (ImageAttributes Attributes = new ImageAttributes()) 
       { 
        Attributes.SetColorMatrix(NewColorMatrix); 
        NewGraphics.DrawImage(OriginalImage, 
         new System.Drawing.Rectangle(0, 0, OriginalImage.Width, OriginalImage.Height), 
         0, 0, OriginalImage.Width, OriginalImage.Height, 
         GraphicsUnit.Pixel, 
         Attributes); 
       } 
      } 
      return NewBitmap; 
     } 

     #endregion 
    } 
} 


/// <summary> 
/// Converts an image to black and white 
/// </summary> 
/// <param name="Image">Image to change</param> 
/// <returns>A bitmap object of the black and white image</returns> 
public static Bitmap ConvertBlackAndWhite(Bitmap Image) 
{ 
    ColorMatrix TempMatrix = new ColorMatrix(); 
    TempMatrix.Matrix = new float[][]{ 
        new float[] {.3f, .3f, .3f, 0, 0}, 
        new float[] {.59f, .59f, .59f, 0, 0}, 
        new float[] {.11f, .11f, .11f, 0, 0}, 
        new float[] {0, 0, 0, 1, 0}, 
        new float[] {0, 0, 0, 0, 1} 
       }; 
    return TempMatrix.Apply(Image); 
} 

float[][] FloatColorMatrix ={ 
     new float[] {1, 0, 0, 0, 0}, 
     new float[] {0, 1, 0, 0, 0}, 
     new float[] {0, 0, 1, 0, 0}, 
     new float[] {0, 0, 0, 1, 0}, 
     new float[] {0, 0, 0, 0, 1} 
    }; 

Answer 5

您可以使用ImageMagick這一點。可以通過命令行Process.Start運行它，也可以使用屬於Windows安裝的COM接口。選項「-monochrome」是你的朋友。

Answer 6

發佈工作由Chuck康威解決方案的版本

/* 
Copyright (c) 2010 <a href="http://www.gutgames.com">James Craig</a> 

Permission is hereby granted, free of charge, to any person obtaining a copy 
of this software and associated documentation files (the "Software"), to deal 
in the Software without restriction, including without limitation the rights 
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
copies of the Software, and to permit persons to whom the Software is 
furnished to do so, subject to the following conditions: 

The above copyright notice and this permission notice shall be included in 
all copies or substantial portions of the Software. 

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
THE SOFTWARE.*/ 

using System.Drawing; 
using System.Drawing.Imaging; 

namespace WebCamService { 
    class ColorMatrix { 

     public float[][] Matrix { get; set; } 

     public Bitmap Apply(Bitmap OriginalImage) { 
      using (Graphics NewGraphics = Graphics.FromImage(OriginalImage)) { 
       System.Drawing.Imaging.ColorMatrix NewColorMatrix = new System.Drawing.Imaging.ColorMatrix(Matrix); 
       using (ImageAttributes Attributes = new ImageAttributes()) { 
        Attributes.SetColorMatrix(NewColorMatrix); 
        NewGraphics.DrawImage(OriginalImage, 
         new System.Drawing.Rectangle(0, 0, OriginalImage.Width, OriginalImage.Height), 
         0, 0, OriginalImage.Width, OriginalImage.Height, 
         GraphicsUnit.Pixel, 
         Attributes); 
       } 
      } 
      return OriginalImage; 
     } 

     public static Bitmap ConvertBlackAndWhite(Bitmap Image) { 
      ColorMatrix TempMatrix = new ColorMatrix(); 
      TempMatrix.Matrix = new float[][]{ 
        new float[] {.3f, .3f, .3f, 0, 0}, 
        new float[] {.59f, .59f, .59f, 0, 0}, 
        new float[] {.11f, .11f, .11f, 0, 0}, 
        new float[] {0, 0, 0, 1, 0}, 
        new float[] {0, 0, 0, 0, 1} 
       }; 
      return TempMatrix.Apply(Image); 
     } 


    } 
}