生成单色BMP图片

在项目的属性里要勾选 容许不安全代码

 public Bitmap ConvertTo24bppTo1bpp(Bitmap SrcImg)

        {

            unsafe

            {

                byte* SrcPointer, DestPointer;

                int Width, Height, SrcStride, DestStride;

                int X, Y, Index, Sum; ;

                Bitmap DestImg = new Bitmap(SrcImg.Width, SrcImg.Height, PixelFormat.Format1bppIndexed);

                BitmapData SrcData = new BitmapData();

                SrcImg.LockBits(new Rectangle(0, 0, SrcImg.Width, SrcImg.Height), ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb, SrcData);

                BitmapData DestData = new BitmapData();

                DestImg.LockBits(new Rectangle(0, 0, SrcImg.Width, SrcImg.Height), ImageLockMode.ReadWrite, PixelFormat.Format1bppIndexed, DestData);

                Width = SrcImg.Width; Height = SrcImg.Height; SrcStride = SrcData.Stride; DestStride = DestData.Stride;

                for (Y = 0; Y < Height; Y++)

                {

                    SrcPointer = (byte *)SrcData.Scan0 + Y * SrcStride;

                    DestPointer = (byte*)DestData.Scan0 + Y * DestStride;

                    Index = 7; Sum = 0;

                    for (X = 0; X < Width; X++)

                    {

                        if (*SrcPointer + (*(SrcPointer + 1) << 1) + *(SrcPointer + 2)>= 512) Sum += (1 << Index);

                        if (Index == 0)

                        {

                            *DestPointer = (byte)Sum;

                            Sum = 0;

                            Index = 7;

                            DestPointer++;

                        }

                        else

                            Index--;

                        SrcPointer+=3;

                    }

                    if (Index != 7) *DestPointer = (byte)Sum;

                }

                SrcImg.UnlockBits(SrcData);

                DestImg.UnlockBits(DestData);

                return DestImg;

            }

        }