彩色图像转黑白图像
大哥们: 
             小弟在往位图里绘制文字时,发现画上去的文字边缘有灰色成份,这样我如果生成一张黑白图像的话,文字就不饱满了。请问该如何解决这个问题。
------解决方案--------------------取消字体边沿自动处理
------解决方案--------------------没有做过图形方面。   
 顶你一把       
------解决方案--------------------up
------解决方案--------------------//-下面函数 往图片上加字   
 		private string overlay(string imgSrc1,int imgLeft1,int imgTop1,string strFont1,string strSize1,string strColor1,string strText1,double cur_width,double cur_height) 
 		{ 
 			//Response.Write( " <script> alert( ' "+strColor1+ " '); </script>  "); 
 			//int lenImage1=imgSrc1.Length-4;			 
 			DateTime now1=DateTime.Now; 
 			string RD=now1.ToString( "yyyyMMddHHmmss "); 
 			string imgPath=imgSrc1.Substring(imgSrc1.IndexOf( "/upimages/ ")+10);; 
 			//imgPath=imgPath.Substring(imgPath.IndexOf( '/ ')+1); 
 			//imgPath=imgPath.Substring(imgPath.IndexOf( '/ ')+1); 
 			imgPath=imgPath.Substring(0,imgPath.LastIndexOf( '/ ')+1); 
 			string imgName=imgSrc1.Substring(imgSrc1.LastIndexOf( '/ ')+1); 
 			string subGet=imgSrc1.Substring(imgSrc1.LastIndexOf( '. ')); 
 			string sd=Session.SessionID.ToString(); 
 			string newImgSrc= " "; 
 			newImgSrc=Server.MapPath( "upimages\\diytemp\\ ")+sd+RD+RD+subGet;  			 
 			string tempPath=Server.MapPath( "upimages/ "+imgPath)+imgName;   
 			double imageWidth=0; 
 			double imageHigh=0;   
 			//取图片像素 
 			System.Drawing.Image oldImage=System.Drawing.Image.FromFile(tempPath); 
 			//根据比例 缩小 
 			imageWidth=cur_width; 
 			imageHigh =cur_height; 
 			// 生成缩微图 .JPG! 
 			System.Drawing.Image thumbnailImage =oldImage.GetThumbnailImage((int)imageWidth,(int)imageHigh,new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback), IntPtr.Zero); 
 			Bitmap output=new Bitmap(thumbnailImage); 
 			//存储类型 
 			output.Save(newImgSrc,System.Drawing.Imaging.ImageFormat.Jpeg); 
 			//释放资源 
 			output.Dispose(); 
 			oldImage.Dispose(); 
 			thumbnailImage.Dispose(); 
 			//RenderImage(imgSrc1,strText1,newImgSrc); 
 			System.Drawing.Image oldImage1=System.Drawing.Image.FromFile(newImgSrc); 
 			Bitmap myBitmap1 = new Bitmap(oldImage1); 
 			Graphics g = Graphics.FromImage(myBitmap1);   
 			Font aFont=new Font(strFont1,(float)(int.Parse(strSize1)),System.Drawing.GraphicsUnit.Point); 
 			Brush aBrush=new SolidBrush(System.Drawing.ColorTranslator.FromHtml(strColor1)); 
 			g.DrawString(strText1,aFont,aBrush,imgLeft1,imgTop1,System.Drawing.StringFormat.GenericTypographic); 
 			//g.DrawString(strText1,aFont,System.Drawing.Brushes.Blue,rec); 
 			newImgSrc=Server.MapPath( "upimages\\diytemp\\ ")+sd+RD+subGet; 
 			myBitmap1.Save(newImgSrc,System.Drawing.Imaging.ImageFormat.Jpeg); 
 			// 清除缓冲  
 			//Response.Clear(); 
 			aFont.Dispose(); 
 			oldImage1.Dispose(); 
 			myBitmap1.Dispose(); 
 			g.Dispose();   
 			txtlenImage+=1; 
 			txttimeImage=RD;   
 			string imgsrc= "upimages/diytemp/ "+sd+RD+subGet; 
 			return imgsrc; 
 		}
------解决方案--------------------up
------解决方案--------------------先写一次白色的文字做底 
 在左上移一个像素写一次黑色的文字 
 就不管背景是啥都能看清除文字。