无损JBIG2编码库(Lossless JBIG2 Encoder)

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C# 的调用方法

调用 JBIG2Encoder 类的 Encode 方法即可，该方法的传入参数为一位图：

///<summary>JBIG2 Lossless Encoder Wrapper</summary>
public static class JBig2Encoder
{
static uint White = 0x00FFFFFF;

public static byte[] Encode (Bitmap bmp, bool zeroIsWhite) {
var bits = bmp.LockBits (new System.Drawing.Rectangle (0, 0, bmp.Width, bmp.Height), System.Drawing.Imaging.ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format1bppIndexed);
var bytes = Encode (bmp.Width, bmp.Height, bits.Stride, zeroIsWhite, bits.Scan0);
bmp.UnlockBits (bits);
return bytes;
}

private static byte[] Encode (int width, int height, int stride, bool zeroIsWhite, IntPtr b) {
int l = 0;
var r = NativeMethods.jbig2_encode (width, height, stride, zeroIsWhite, b, ref l);
byte[] result = new byte[l];
Marshal.Copy (r, result, 0, l);
NativeMethods.release (r);
return result;
}

class NativeMethods
{
[DllImport ("jbig2enc.dll")]
internal static extern IntPtr jbig2_encode (int width, int height, int stride, bool zeroIsWhite, IntPtr data, ref int length);

[DllImport ("jbig2enc.dll")]
internal static extern IntPtr release (IntPtr data);
}
} >