C＃转换图像来完成黑白

Question

我有一个GIF图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！）简单地通过减少他使用2（黑&白）色数。

我想做同样的事情在我的应用程序，但所有我能找到的转向图像为灰度它把我的160KB的GIF 100KB。

反正把我的GIF为COMPLETE黑白？任何其他方式，可以缩小GIF到更小的尺寸将不胜感激。

Answer 1

下面是如何把它变成一个黑白G4压缩的TIFF一个codeproject example。请注意，对于包含大量空白和文本的图像而言，这非常好，但对图像不太好。使用图片时，您可能希望看到其他答案并使用抖动。

Answer 2

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

或者，如果你不需要抖动，发现平均亮度，打开上面的所有像素为白色，低于为黑色。

Answer 3

这里有一些代码对SO：Bayer Ordered Dithering那是应该做的，我认为（未测试）。值得一试。

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这一点。可以通过命令行Process.Start运行它，也可以使用属于Windows安装的COM接口。选项“-monochrome”是你的朋友。

Answer 6

发布工作由Chuck康威解决方案的版本

/* 
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); 
     } 


    } 
}