From: Tae-Young Chung <ty83.chung@samsung.com>
Date: Mon, 25 Oct 2021 06:58:24 +0000 (+0900)
Subject: Add downscaling to reduce execution time
X-Git-Tag: submit/tizen/20220701.002357~1^2~16
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=67bc51243bc2137001d16cc5ef2751a4e555a55d;p=platform%2Fcore%2Fmultimedia%2Fdfs-opencv.git

Add downscaling to reduce execution time

Before running compute() for disparity estimation,
resize the input images' size to half in both width and height.
After compute(), resize the size to the original size.
The, apply WLS filter as post-process.

Signed-off-by: Tae-Young Chung <ty83.chung@samsung.com>
---

diff --git a/src/dfs_opencv.cpp b/src/dfs_opencv.cpp
index 055f956..c435ba3 100644
--- a/src/dfs_opencv.cpp
+++ b/src/dfs_opencv.cpp
@@ -17,6 +17,7 @@
 #include "dfs_opencv_private.h"
 #include <dlog.h>
 #include <opencv2/core/persistence.hpp>
+#include <opencv2/imgcodecs.hpp>
 
 #define DEFAULT_STEREO_CALIB_FILE_NAME "stereoCalibZed.yaml"
 #define DEFAULT_STEREO_VGA_CALIB_FILE_NAME "stereoCalibZedVGA.yaml"
@@ -26,6 +27,7 @@ namespace DfsAdaptationImpl
 {
 	DfsOCV::DfsOCV() :
 		mDfsOcv(nullptr),
+		mDfsOcvExtra(nullptr),
 		mDfsPostOcv(nullptr),
 		mDfsParam(),
 		mNumDisparities(179),
@@ -40,7 +42,8 @@ namespace DfsAdaptationImpl
 		mStereoParam(),
 		mIsStereoCalibrated(false),
 		mUpdateStereoCalibration(false),
-		mImageSize(cv::Size(0,0))
+		mImageSize(cv::Size(0,0)),
+		mDownScale(1)
 	{
 		LOGI("ENTER");
 		LOGI("LEAVE");
@@ -161,6 +164,10 @@ namespace DfsAdaptationImpl
 
 		mDfsParam = param;
 		mImageSize = cv::Size(width, height);
+		if (mDownScale) {
+			mMinDisparity >>= mDownScale;
+			mNumDisparities >>= mDownScale;
+		}
 		mDfsOcv = cv::StereoSGBM::create(mMinDisparity, mNumDisparities, mBlockSize);
 
 		this->SetParameters();
@@ -172,10 +179,10 @@ namespace DfsAdaptationImpl
 			throw e;
 		}
 
-#if 0
+#if 0 // oneway
 		mDfsPostOcv = cv::ximgproc::createDisparityWLSFilterGeneric(false);
 		mDfsPostOcv->setDepthDiscontinuityRadius(static_cast<int>(ceil(0.5*mBlockSize)));
-#else
+#else // twoway
 		mDfsPostOcv = cv::ximgproc::createDisparityWLSFilter(mDfsOcv);
 		mDfsOcvExtra = cv::ximgproc::createRightMatcher(mDfsOcv);
 		mDfsPostOcv->setLRCthresh(24.0);
@@ -252,22 +259,67 @@ namespace DfsAdaptationImpl
 		cv::remap(baseMat, rBaseMat, mBaseReMap[0], mBaseReMap[1], cv::INTER_LINEAR);
 		cv::remap(extraMat, rExtraMat, mExtraReMap[0], mExtraReMap[1], cv::INTER_LINEAR);
 
-		mDfsOcv->compute(rBaseMat, rExtraMat, dispMat);
+		cv::Mat srcBaseMat, srcExtraMat;
+		cv::resize(rBaseMat, srcBaseMat,
+					cv::Size(),
+					1.0/static_cast<double>((1<<mDownScale)),
+					1.0/static_cast<double>((1<<mDownScale)));
+		cv::resize(rExtraMat, srcExtraMat,
+					cv::Size(),
+					1.0/static_cast<double>((1<<mDownScale)),
+					1.0/static_cast<double>((1<<mDownScale)));
+
+		mDfsOcv->compute(srcBaseMat, srcExtraMat, dispMat);
 		if (mDfsPostOcv) {
 			if (mDfsOcvExtra) {
 				cv::Mat dispMatExtra;
-				mDfsOcvExtra->compute(rExtraMat, rBaseMat, dispMatExtra);
-
+				mDfsOcvExtra->compute(srcExtraMat, srcBaseMat, dispMatExtra);
+
+				if (mDownScale) {
+					cv::Mat tmp;
+					// base
+					cv::resize(dispMat, tmp,
+					cv::Size(),
+					static_cast<double>(1<<mDownScale),
+					static_cast<double>(1<<mDownScale));
+					dispMat = tmp * static_cast<double>(1<<mDownScale);
+
+					// extra
+					cv::resize(dispMatExtra, tmp,
+					cv::Size(),
+					static_cast<double>(1<<mDownScale),
+					static_cast<double>(1<<mDownScale));
+					dispMatExtra = tmp * static_cast<double>(1<<mDownScale);
+				}
 				mDfsPostOcv->filter(dispMat, rBaseMat, dispFiltMat,
 									dispMatExtra,
 									cv::Rect(0,0,rBaseMat.cols, rBaseMat.rows),
 									rExtraMat);
 			} else {
+				if (mDownScale) {
+					cv::Mat tmp;
+					cv::resize(dispMat, tmp,
+					cv::Size(),
+					static_cast<double>(1<<mDownScale),
+					static_cast<double>(1<<mDownScale));
+					dispMat = tmp * static_cast<double>(1<<mDownScale);
+				}
 				mDfsPostOcv->filter(dispMat, rBaseMat, dispFiltMat);
 			}
+
 			dispFiltMat.convertTo(mDispMat, CV_8UC1, 1.0/16.0);
 		} else {
-			dispMat.convertTo(mDispMat, CV_8UC1, 1.0/16.0);
+			if (mDownScale) {
+				cv::Mat tmp;
+				cv::resize(dispMat, tmp,
+					cv::Size(),
+					static_cast<double>(1<<mDownScale),
+					static_cast<double>(1<<mDownScale));
+
+				tmp.convertTo(mDispMat, CV_8UC1, (1.0/16.0) * static_cast<double>(1 << mDownScale));
+			} else {
+				dispMat.convertTo(mDispMat, CV_8UC1, 1.0/16.0);
+			}
 		}
 
 		mDepthData.data = mDispMat.ptr<unsigned char>();
diff --git a/src/dfs_opencv_private.h b/src/dfs_opencv_private.h
index d47adac..1467860 100644
--- a/src/dfs_opencv_private.h
+++ b/src/dfs_opencv_private.h
@@ -94,6 +94,8 @@ namespace DfsAdaptationImpl
 		cv::Mat mBaseReMap[2];
 		cv::Mat mExtraReMap[2];
 
+		size_t mDownScale;
+
 		void SetParameters();
 		int  ConvertDfsDataTypeToCV(int type);
 		void InitializeStereoCalibration();