diff --git a/hgdriver/hgdev/hg_scanner.cpp b/hgdriver/hgdev/hg_scanner.cpp
index a95848c..64cb7b9 100644
--- a/hgdriver/hgdev/hg_scanner.cpp
+++ b/hgdriver/hgdev/hg_scanner.cpp
@@ -13,6 +13,73 @@ static int ui_default_callback(scanner_handle, int, void*, unsigned int*, void*)
 {
 	return 0;
 }
+static std::string bmp_821(unsigned char* bits/*bits data*/, int w, int h, int* lbytes, bool line_align_4)
+{
+	static unsigned int g_bmp8_pallete[] = {
+					  0x00000000, 0x00800000, 0x00008000, 0x00808000, 0x00000080, 0x00800080, 0x00008080,   0x00c0c0c0, 0x00c0dcc0, 0x00a6caf0, 0x00402000, 0x00602000, 0x00802000, 0x00a02000, 0x00c02000, 0x00e02000
+					, 0x00004000, 0x00204000, 0x00404000, 0x00604000, 0x00804000, 0x00a04000, 0x00c04000,   0x00e04000, 0x00006000, 0x00206000, 0x00406000, 0x00606000, 0x00806000, 0x00a06000, 0x00c06000, 0x00e06000
+					, 0x00008000, 0x00208000, 0x00408000, 0x00608000, 0x00808000, 0x00a08000, 0x00c08000,   0x00e08000, 0x0000a000, 0x0020a000, 0x0040a000, 0x0060a000, 0x0080a000, 0x00a0a000, 0x00c0a000, 0x00e0a000
+					, 0x0000c000, 0x0020c000, 0x0040c000, 0x0060c000, 0x0080c000, 0x00a0c000, 0x00c0c000,   0x00e0c000, 0x0000e000, 0x0020e000, 0x0040e000, 0x0060e000, 0x0080e000, 0x00a0e000, 0x00c0e000, 0x00e0e000
+					, 0x00000040, 0x00200040, 0x00400040, 0x00600040, 0x00800040, 0x00a00040, 0x00c00040,   0x00e00040, 0x00002040, 0x00202040, 0x00402040, 0x00602040, 0x00802040, 0x00a02040, 0x00c02040, 0x00e02040
+					, 0x00004040, 0x00204040, 0x00404040, 0x00604040, 0x00804040, 0x00a04040, 0x00c04040,   0x00e04040, 0x00006040, 0x00206040, 0x00406040, 0x00606040, 0x00806040, 0x00a06040, 0x00c06040, 0x00e06040
+					, 0x00008040, 0x00208040, 0x00408040, 0x00608040, 0x00808040, 0x00a08040, 0x00c08040,   0x00e08040, 0x0000a040, 0x0020a040, 0x0040a040, 0x0060a040, 0x0080a040, 0x00a0a040, 0x00c0a040, 0x00e0a040
+					, 0x0000c040, 0x0020c040, 0x0040c040, 0x0060c040, 0x0080c040, 0x00a0c040, 0x00c0c040,   0x00e0c040, 0x0000e040, 0x0020e040, 0x0040e040, 0x0060e040, 0x0080e040, 0x00a0e040, 0x00c0e040, 0x00e0e040
+					, 0x00000080, 0x00200080, 0x00400080, 0x00600080, 0x00800080, 0x00a00080, 0x00c00080,   0x00e00080, 0x00002080, 0x00202080, 0x00402080, 0x00602080, 0x00802080, 0x00a02080, 0x00c02080, 0x00e02080
+					, 0x00004080, 0x00204080, 0x00404080, 0x00604080, 0x00804080, 0x00a04080, 0x00c04080,   0x00e04080, 0x00006080, 0x00206080, 0x00406080, 0x00606080, 0x00806080, 0x00a06080, 0x00c06080, 0x00e06080
+					, 0x00008080, 0x00208080, 0x00408080, 0x00608080, 0x00808080, 0x00a08080, 0x00c08080,   0x00e08080, 0x0000a080, 0x0020a080, 0x0040a080, 0x0060a080, 0x0080a080, 0x00a0a080, 0x00c0a080, 0x00e0a080
+					, 0x0000c080, 0x0020c080, 0x0040c080, 0x0060c080, 0x0080c080, 0x00a0c080, 0x00c0c080,   0x00e0c080, 0x0000e080, 0x0020e080, 0x0040e080, 0x0060e080, 0x0080e080, 0x00a0e080, 0x00c0e080, 0x00e0e080
+					, 0x000000c0, 0x002000c0, 0x004000c0, 0x006000c0, 0x008000c0, 0x00a000c0, 0x00c000c0,   0x00e000c0, 0x000020c0, 0x002020c0, 0x004020c0, 0x006020c0, 0x008020c0, 0x00a020c0, 0x00c020c0, 0x00e020c0
+					, 0x000040c0, 0x002040c0, 0x004040c0, 0x006040c0, 0x008040c0, 0x00a040c0, 0x00c040c0,   0x00e040c0, 0x000060c0, 0x002060c0, 0x004060c0, 0x006060c0, 0x008060c0, 0x00a060c0, 0x00c060c0, 0x00e060c0
+					, 0x000080c0, 0x002080c0, 0x004080c0, 0x006080c0, 0x008080c0, 0x00a080c0, 0x00c080c0,   0x00e080c0, 0x0000a0c0, 0x0020a0c0, 0x0040a0c0, 0x0060a0c0, 0x0080a0c0, 0x00a0a0c0, 0x00c0a0c0, 0x00e0a0c0
+					, 0x0000c0c0, 0x0020c0c0, 0x0040c0c0, 0x0060c0c0, 0x0080c0c0, 0x00a0c0c0, 0x00fffbf0,   0x00a0a0a4, 0x00808080, 0x00ff0000, 0x0000ff00, 0x00ffff00, 0x000000ff, 0x00ff00ff, 0x0000ffff, 0x00ffffff			
+				};
+	int			l = (w + 31) / 32 * 4,
+				size = l * h,
+				line_bytes = (w + 3) / 4 * 4;
+	std::string	f("");
+	unsigned char* data = nullptr;
+	unsigned int*	pallete = g_bmp8_pallete;
+	
+	if (!line_align_4)
+	{
+		l = (w + 7) / 8;
+		size = l * h;
+	}
+	if (lbytes && *lbytes)
+		line_bytes = *lbytes;
+	f.resize(size);
+	data = (unsigned char*)&f[0];
+	for (int i = 0; i < h; ++i)
+	{
+		unsigned char v = 0,
+					*dst = data;
+		for (int j = 0; j < w; ++j)
+		{
+			v <<= 1;
+
+			unsigned char pixel = ((pallete[bits[j]] & 0x0ff) + ((pallete[bits[j]] >> 8) & 0x0ff) + ((pallete[bits[j]] >> 16) & 0x0ff)) / 3;
+			if (pixel >= 128)
+				v |= 1;
+			if ((j + 1) % 8 == 0)
+			{
+				*dst++ = v;
+				v = 0;
+			}
+		}
+		if (v)
+		{
+			v <<= 8 - (w % 8);
+			*dst++ = v;
+		}
+
+		data += l;
+		bits += line_bytes;
+	}
+	if (lbytes)
+		*lbytes = l;
+
+	return f;
+}
 
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // hg_scanner
@@ -1737,14 +1804,14 @@ bool hg_scanner::waiting_for_memory_enough(unsigned need_bytes)
 	return ret;
 }
 
-void hg_scanner::copy_to_sane_image_header(SANE_Parameters* header, int w, int h, int line_bytes, int channels)
+void hg_scanner::copy_to_sane_image_header(SANE_Parameters* header, int w, int h, int line_bytes, int channels, int bits)
 {
 	if (channels == 3)
 		header->format = SANE_FRAME_RGB;
 	else
 		header->format = SANE_FRAME_GRAY;
-	header->depth = 8;				// 此处指每一个颜色分量的位深，我们的扫描仪固定为“8”
-	header->last_frame = SANE_TRUE;	// 一幅图片如果各个分量相互分离，则最后一个分量的时候设置为true。彩色图像RGB时也只有一“帧”，所以也为true
+	header->depth = bits >= 8 ? 8 : bits;	// 此处指每一个颜色分量的位深，我们的扫描仪固定为“8”
+	header->last_frame = SANE_TRUE;			// 一幅图片如果各个分量相互分离，则最后一个分量的时候设置为true。彩色图像RGB时也只有一“帧”，所以也为true
 	header->pixels_per_line = w;
 	header->lines = h;
 	header->bytes_per_line = line_bytes;
@@ -1778,11 +1845,23 @@ int hg_scanner::save_usb_data(std::shared_ptr<std::vector<char>> data)
 }
 int hg_scanner::save_final_image(hg_imgproc::LPIMGHEAD head, void* buf)
 {
+	std::string bw("");
+
 	final_img_index_++;
+	if (image_prc_param_.bits.color_mode == COLOR_MODE_BLACK_WHITE)
+	{
+		int old = head->line_bytes;
+		bw = bmp_821((unsigned char*)buf, head->width, head->height, &head->line_bytes, async_io_);
+		buf = &bw[0];
+		head->channels = head->bits = 1;
+		head->total_bytes = head->line_bytes * head->height;
+		VLOG_MINI_4(LOG_LEVEL_DEBUG_INFO, "convert to 1-bit bmp(%d * %d), total = %u, len = %u\n", head->width, head->height, head->total_bytes, bw.length());
+	}
+
 	if (async_io_)
 	{
 		SANE_Image	img;
-		copy_to_sane_image_header(&img.header, head->width, head->height, head->line_bytes, head->channels);
+		copy_to_sane_image_header(&img.header, head->width, head->height, head->line_bytes, head->channels, head->bits);
 		img.data = (unsigned char*)buf;
 		img.bytes = head->total_bytes;
 
@@ -2153,7 +2232,7 @@ int hg_scanner::get_image_info(SANE_Parameters* ii)
 		if (!final_imgs_.front(&imh))
 			ret = SCANNER_ERR_NO_DATA;
 		else
-			copy_to_sane_image_header(ii, imh.width, imh.height, imh.line_bytes, imh.channels);
+			copy_to_sane_image_header(ii, imh.width, imh.height, imh.line_bytes, imh.channels, imh.bits);
 	}
 
 	if (ret == SCANNER_ERR_NO_DATA /*&& final_img_index_ == 0*/)
@@ -2162,7 +2241,7 @@ int hg_scanner::get_image_info(SANE_Parameters* ii)
 			ret = SCANNER_ERR_NO_DATA;
 		else
 		{
-			ii->depth = 8;
+			ii->depth = image_prc_param_.bits.color_mode == COLOR_MODE_BLACK_WHITE ? 1 : 8;
 			ii->last_frame = SANE_TRUE;
 			ii->format = image_prc_param_.bits.color_mode == COLOR_MODE_24_BITS || image_prc_param_.bits.color_mode == COLOR_MODE_AUTO_MATCH ?
 				SANE_FRAME_RGB : SANE_FRAME_GRAY;
diff --git a/hgdriver/hgdev/hg_scanner.h b/hgdriver/hgdev/hg_scanner.h
index 8d0b467..dfbdf44 100644
--- a/hgdriver/hgdev/hg_scanner.h
+++ b/hgdriver/hgdev/hg_scanner.h
@@ -268,7 +268,7 @@ protected:
     int notify_ui_working_status(const char* msg, int ev = SANE_EVENT_STATUS, int status = SCANNER_ERR_OK);
     bool waiting_for_memory_enough(unsigned need_bytes);
 
-    void copy_to_sane_image_header(SANE_Parameters* header, int w, int h, int line_bytes, int channels);
+    void copy_to_sane_image_header(SANE_Parameters* header, int w, int h, int line_bytes, int channels, int bits);
     int save_usb_data(std::shared_ptr<std::vector<char>> data);
     int save_final_image(hg_imgproc::LPIMGHEAD head, void* buf);