diff --git a/hgdriver/3rdparty/opencv/include/win/opencv2/imgcodecs/imgcodecs_c.h b/hgdriver/3rdparty/opencv/include/win/opencv2/imgcodecs/imgcodecs_c.h
index c36dac3..e821999 100644
--- a/hgdriver/3rdparty/opencv/include/win/opencv2/imgcodecs/imgcodecs_c.h
+++ b/hgdriver/3rdparty/opencv/include/win/opencv2/imgcodecs/imgcodecs_c.h
@@ -85,6 +85,13 @@ enum
     CV_IMWRITE_JPEG_RST_INTERVAL =4,
     CV_IMWRITE_JPEG_LUMA_QUALITY =5,
     CV_IMWRITE_JPEG_CHROMA_QUALITY =6,
+
+    // add for DPI on 2022-10-14
+    CV_IMWRITE_JPEG_RESOLUTION_UNIT = 7,    // 0 - unknown(default value), 1 - dots/inch, 2 - dots/cm
+    CV_IMWRITE_JPEG_RESOLUTION_X = 8,       // default value - 1
+    CV_IMWRITE_JPEG_RESOLUTION_Y = 9,       // default value - 1
+    // ENDED for DPI
+
     CV_IMWRITE_PNG_COMPRESSION =16,
     CV_IMWRITE_PNG_STRATEGY =17,
     CV_IMWRITE_PNG_BILEVEL =18,
diff --git a/hgdriver/hgdev/image_process.cpp b/hgdriver/hgdev/image_process.cpp
index 773af57..69febc6 100644
--- a/hgdriver/hgdev/image_process.cpp
+++ b/hgdriver/hgdev/image_process.cpp
@@ -1399,8 +1399,16 @@ namespace hg_imgproc
 			// MSB word[7] and word[8] are x and y resolutions
 			std::vector<int>	cpr;
 			unsigned short		jpeg_r = (resolution << 8) | ((resolution >> 8) & 0x0ff);
+			int		resolution_y = bih.biYPelsPerMeter / 39.37f + .5f;
+
 			cpr.push_back(CV_IMWRITE_JPEG_QUALITY);
 			cpr.push_back((int)(long)conv->dst.fmt.detail);
+			cpr.push_back(CV_IMWRITE_JPEG_RESOLUTION_UNIT);
+			cpr.push_back(1);
+			cpr.push_back(CV_IMWRITE_JPEG_RESOLUTION_X);
+			cpr.push_back(resolution);
+			cpr.push_back(CV_IMWRITE_JPEG_RESOLUTION_Y);
+			cpr.push_back(resolution_y);
 			if (conv->dst.is_file)
 			{
 				cv::imwrite(conv->dst.data, imsg, cpr);