modules/ocl/cv_feature_match_cluster.cpp - platform/external/libxcam - Git at Google

 /*
  * cv_feature_match_cluster.cpp - optical flow feature match selected by clustering
  *
  *  Copyright (c) 2016-2017 Intel Corporation
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *   http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
  * Author: Wu Junkai <[email protected]>
  */

 #include "cv_feature_match_cluster.h"
 #include "xcam_obj_debug.h"
 #include "image_file_handle.h"

 #define XCAM_CV_FM_DEBUG 0
 #define XCAM_CV_OF_DRAW_SCALE 2

 namespace XCam {
 CVFeatureMatchCluster::CVFeatureMatchCluster ()
     : CVFeatureMatch ()
 {
 }

 bool
 CVFeatureMatchCluster::calc_mean_offset (
     std::vector<cv::Point2f> &corner0, std::vector<cv::Point2f> &corner1,
     std::vector<uchar> &status, std::vector<float> &error,
     float &mean_offset_x, float &mean_offset_y,
     cv::InputOutputArray debug_img, cv::Size &img0_size, cv::Size &img1_size)
 {
     std::vector<std::vector<uint32_t>> clusters;
     std::vector<std::vector<cv::Point2f>> clusters_offsets;
     std::vector<uint32_t> valid_seeds (status.size ());
     std::vector<uint32_t> valid_corners (status.size ());

     for (uint32_t i = 0; i < status.size (); ++i) {
         if (!status[i] || (error[i] > _config.max_track_error) || corner1[i].x < 0.0f || corner1[i].x > img0_size.width) {
             valid_corners[i] = 0;
             valid_seeds[i] = 0;
         } else {
             valid_corners[i] = 1;
             valid_seeds[i] = 1;
         }
     }

     float seed_x_offset = 0.0f;
     float seed_y_offset = 0.0f;

     std::vector<uint32_t> cluster (1);
     std::vector<cv::Point2f> cluster_offset (1);

     float thres = 8.0f;
     while (cluster.size() > 0) {
         cluster.clear ();
         cluster_offset.clear ();

         for (uint32_t i = 0; i < status.size (); ++i) {
             if (valid_seeds[i]) {
                 seed_x_offset = corner1[i].x - corner0[i].x;
                 seed_y_offset = corner1[i].y - corner0[i].y;
                 cluster.push_back (i);
                 cluster_offset.push_back (cv::Point2f(seed_x_offset, seed_y_offset));
                 valid_corners[i] = 0;
                 valid_seeds[i] = 0;
                 break;
             }
         }

         if (cluster.size() > 0) {
             for (uint32_t i = 0; i < status.size (); ++i) {
                 if (!valid_corners[i])
                     continue;

                 float x_offset = corner1[i].x - corner0[i].x;
                 float y_offset = corner1[i].y - corner0[i].y;

                 if (fabs (x_offset - seed_x_offset) > thres || fabs (y_offset - seed_y_offset) > thres / 2.0f)
                     continue;

                 cluster.push_back (i);
                 cluster_offset.push_back (cv::Point2f(x_offset, y_offset));
                 valid_seeds[i] = 0;
             }

             clusters.push_back (cluster);
             clusters_offsets.push_back (cluster_offset);
         }
     }

     if (clusters_offsets.size () == 0)
         return false;

     uint32_t max_size = 0;
     uint32_t max_index = 0;

     for (uint32_t i = 0; i < clusters.size (); ++i) {
         if (clusters[i].size () > max_size) {
             max_size = clusters[i].size ();
             max_index = i;
         }
     }

     if (clusters_offsets[max_index].size () < (uint32_t)_config.min_corners)
         return false;

     float sum_x = 0.0f;
     float sum_y = 0.0f;
     for (uint32_t i = 0; i < clusters_offsets[max_index].size (); ++i) {
         sum_x += clusters_offsets[max_index][i].x;
         sum_y += clusters_offsets[max_index][i].y;
     }

     mean_offset_x = sum_x / clusters_offsets[max_index].size ();
     mean_offset_y = sum_y / clusters_offsets[max_index].size ();

 #if XCAM_CV_FM_DEBUG
     for (uint32_t i = 0; i < status.size (); ++i) {
         if(!status[i])
             continue;

         cv::Point start = cv::Point(corner0[i]) * XCAM_CV_OF_DRAW_SCALE;
         cv::circle (debug_img, start, 4, cv::Scalar(0), XCAM_CV_OF_DRAW_SCALE);
         cv::Point end = (cv::Point(corner1[i]) + cv::Point (img0_size.width, 0)) * XCAM_CV_OF_DRAW_SCALE;
         cv::line (debug_img, start, end, cv::Scalar(0), XCAM_CV_OF_DRAW_SCALE);
     }

     for (uint32_t i = 0; i < status.size (); ++i) {
         if (!status[i])
             continue;

         cv::Point start = cv::Point(corner0[i]) * XCAM_CV_OF_DRAW_SCALE;
         cv::circle (debug_img, start, 4, cv::Scalar(0), XCAM_CV_OF_DRAW_SCALE);
         if (error[i] > _config.max_track_error)
             continue;
         if (fabs(corner0[i].y - corner1[i].y) >= _config.max_valid_offset_y)
             continue;
         if (corner1[i].x < 0.0f || corner1[i].x > img0_size.width)
             continue;

         cv::Point end = (cv::Point(corner1[i]) + cv::Point (img0_size.width, 0)) * XCAM_CV_OF_DRAW_SCALE;
         cv::line (debug_img, start, end, cv::Scalar(255), XCAM_CV_OF_DRAW_SCALE);
     }

     for (uint32_t i = 0; i < status.size (); ++i) {
         if(!status[i])
             continue;

         cv::Point start = (cv::Point(corner0[i]) + cv::Point (img0_size.width + img1_size.width, 0)) * XCAM_CV_OF_DRAW_SCALE;
         cv::circle (debug_img, start, 4, cv::Scalar(0), XCAM_CV_OF_DRAW_SCALE);
         cv::Point end = (cv::Point(corner1[i]) + cv::Point (2 * img0_size.width + img1_size.width, 0)) * XCAM_CV_OF_DRAW_SCALE;
         cv::line (debug_img, start, end, cv::Scalar(0), XCAM_CV_OF_DRAW_SCALE);
     }

     if (clusters.size () != 0)
         cluster = clusters[max_index];
     for (uint32_t i = 0; i < cluster.size (); ++i) {
         cv::Point start = (cv::Point(corner0[cluster[i]]) + cv::Point(img0_size.width + img1_size.width, 0)) * XCAM_CV_OF_DRAW_SCALE;
         cv::circle (debug_img, start, 4, cv::Scalar(0), XCAM_CV_OF_DRAW_SCALE);
         cv::Point end = (cv::Point(corner1[cluster[i]]) + cv::Point (2 * img0_size.width + img1_size.width, 0)) * XCAM_CV_OF_DRAW_SCALE;
         cv::line (debug_img, start, end, cv::Scalar(255), XCAM_CV_OF_DRAW_SCALE);
     }

 #endif

     XCAM_UNUSED (debug_img);
     XCAM_UNUSED (img0_size);
     XCAM_UNUSED (img1_size);

     clusters.clear ();
     clusters_offsets.clear ();

     return true;
 }

 void
 CVFeatureMatchCluster::calc_of_match_cluster (
     cv::InputArray image0, cv::InputArray image1,
     std::vector<cv::Point2f> &corner0, std::vector<cv::Point2f> &corner1,
     std::vector<uchar> &status, std::vector<float> &error,
     float &last_mean_offset_x, float &last_mean_offset_y,
     float &out_x_offset, float &out_y_offset)
 {
     cv::_InputOutputArray debug_img;
     cv::Size img0_size = image0.size ();
     cv::Size img1_size = image1.size ();
     XCAM_ASSERT (img0_size.height == image1.rows ());
     XCAM_UNUSED (image1);

 #if XCAM_CV_FM_DEBUG
     cv::Mat mat;
     cv::UMat umat;
     cv::Size size ((img0_size.width + img1_size.width) * 2, img0_size.height);

     if (image0.isUMat ()) {
         umat.create (size, image0.type ());
         debug_img = cv::_InputOutputArray (umat);

         image0.copyTo (umat (cv::Rect(0, 0, img0_size.width, img0_size.height)));
         image1.copyTo (umat (cv::Rect(img0_size.width, 0, img1_size.width, img1_size.height)));

         image0.copyTo (umat (cv::Rect(img0_size.width + img1_size.width, 0, img0_size.width, img0_size.height)));
         image1.copyTo (umat (cv::Rect(2 * img0_size.width + img1_size.width, 0, img1_size.width, img1_size.height)));
         umat.copyTo (debug_img);
     } else {
         mat.create (size, image0.type ());
         debug_img = cv::_InputOutputArray (mat);

         image0.copyTo (mat (cv::Rect(0, 0, img0_size.width, img0_size.height)));
         image1.copyTo (mat (cv::Rect(img0_size.width, 0, img1_size.width, img1_size.height)));

         image0.copyTo (mat (cv::Rect(img0_size.width + img1_size.width, 0, img0_size.width, img0_size.height)));
         image1.copyTo (mat (cv::Rect(2 * img0_size.width + img1_size.width, 0, img1_size.width, img1_size.height)));

         mat.copyTo (debug_img);
     }

     cv::Size scale_size = size * XCAM_CV_OF_DRAW_SCALE;
     cv::resize (debug_img, debug_img, scale_size, 0, 0);
 #endif

     float mean_offset_x = 0.0f;
     float mean_offset_y = 0.0f;
     bool ret = calc_mean_offset (corner0, corner1, status, error, mean_offset_x, mean_offset_y, debug_img, img0_size, img1_size);

 #if XCAM_CV_FM_DEBUG
     char file_name[256];
     std::snprintf (file_name, 256, "fm_optical_flow_%d_%d.jpg", _frame_num, _fm_idx);
     cv::imwrite (file_name, debug_img);
 #endif

     if (ret) {
         if (fabs (mean_offset_x - last_mean_offset_x) < _config.delta_mean_offset) {
             out_x_offset = out_x_offset * _config.offset_factor + mean_offset_x * (1.0f - _config.offset_factor);

             if (fabs (out_x_offset) > _config.max_adjusted_offset)
                 out_x_offset = (out_x_offset > 0.0f) ? _config.max_adjusted_offset : (-_config.max_adjusted_offset);
         }

         if (fabs (mean_offset_y - last_mean_offset_y) < _config.delta_mean_offset) {
             out_y_offset = out_y_offset * _config.offset_factor + mean_offset_y * (1.0f - _config.offset_factor);

             if (fabs (out_y_offset) > _config.max_adjusted_offset)
                 out_y_offset = (out_y_offset > 0.0f) ? _config.max_adjusted_offset : (-_config.max_adjusted_offset);
         }
     }

     last_mean_offset_x = mean_offset_x;
     last_mean_offset_y = mean_offset_y;
 }

 void
 CVFeatureMatchCluster::detect_and_match_cluster (
     cv::InputArray img_left, cv::InputArray img_right, Rect &crop_left, Rect &crop_right,
     float &mean_offset_x, float &mean_offset_y, float &x_offset, float &y_offset)
 {
     std::vector<float> err;
     std::vector<uchar> status;
     std::vector<cv::Point2f> corner_left, corner_right;
     cv::Ptr<cv::Feature2D> fast_detector;
     cv::Size win_size = cv::Size (21, 21);

     if (img_left.isUMat ())
         win_size = cv::Size (16, 16);

     fast_detector = cv::FastFeatureDetector::create (20, true);
     add_detected_data (img_left, fast_detector, corner_left);

     if (corner_left.empty ()) {
         return;
     }

     cv::calcOpticalFlowPyrLK (
         img_left, img_right, corner_left, corner_right, status, err, win_size, 3,
         cv::TermCriteria (cv::TermCriteria::COUNT + cv::TermCriteria::EPS, 30, 0.01f));

     calc_of_match_cluster (img_left, img_right, corner_left, corner_right,
                            status, err, mean_offset_x, mean_offset_y, x_offset, y_offset);

 #if XCAM_CV_FM_DEBUG
     XCAM_LOG_INFO ("x_offset:%0.2f", x_offset);
     XCAM_LOG_INFO (
         "FeatureMatch(idx:%d): stiching area: left_area(pos_x:%d, width:%d), right_area(pos_x:%d, width:%d)",
         _fm_idx, crop_left.pos_x, crop_left.width, crop_right.pos_x, crop_right.width);
 #endif

     XCAM_UNUSED (crop_left);
     XCAM_UNUSED (crop_right);
 }

 void
 CVFeatureMatchCluster::optical_flow_feature_match (
     const SmartPtr<VideoBuffer> &left_buf, const SmartPtr<VideoBuffer> &right_buf,
     Rect &left_crop_rect, Rect &right_crop_rect, int dst_width)
 {
 #if HAVE_LIBCL
     cv::UMat left_umat, right_umat;
     if (!get_crop_image_umat (left_buf, left_crop_rect, left_umat, BufId0)
             || !get_crop_image_umat (right_buf, right_crop_rect, right_umat, BufId1))
         return;

     cv::Mat left_mat = left_umat.getMat (cv::ACCESS_READ);
     cv::Mat right_mat = right_umat.getMat (cv::ACCESS_READ);
 #else
     cv::Mat left_mat, left_mat;
     if (!get_crop_image_mat (left_buf, left_crop_rect, left_mat)
             || !get_crop_image_mat (right_buf, right_crop_rect, left_mat))
         return;
 #endif

     cv::_InputArray left_img = cv::_InputArray (left_mat);
     cv::_InputArray right_img = cv::_InputArray (right_mat);

     detect_and_match_cluster (left_img, right_img, left_crop_rect, right_crop_rect,
                               _mean_offset, _mean_offset_y, _x_offset, _y_offset);

 #if XCAM_CV_FM_DEBUG
     XCAM_ASSERT (_fm_idx >= 0);

     char frame_str[64] = {'\0'};
     std::snprintf (frame_str, 64, "frame:%d", _frame_num);
     char fm_idx_str[64] = {'\0'};
     std::snprintf (fm_idx_str, 64, "fm_idx:%d", _fm_idx);

     char img_name[256] = {'\0'};
     std::snprintf (img_name, 256, "fm_in_stitch_area_%d_%d_0.jpg", _frame_num, _fm_idx);
     debug_write_image (left_buf, left_crop_rect, img_name, frame_str, fm_idx_str);

     std::snprintf (img_name, 256, "fm_in_stitch_area_%d_%d_1.jpg", _frame_num, _fm_idx);
     debug_write_image (right_buf, right_crop_rect, img_name, frame_str, fm_idx_str);

     XCAM_LOG_INFO ("FeatureMatch(idx:%d): frame number:%d done", _fm_idx, _frame_num);
     _frame_num++;
 #endif

     XCAM_UNUSED (dst_width);
 }

 }
	/*
	* cv_feature_match_cluster.cpp - optical flow feature match selected by clustering
	*
	* Copyright (c) 2016-2017 Intel Corporation
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*
	* Author: Wu Junkai <[email protected]>
	*/

	#include "cv_feature_match_cluster.h"
	#include "xcam_obj_debug.h"
	#include "image_file_handle.h"

	#define XCAM_CV_FM_DEBUG 0
	#define XCAM_CV_OF_DRAW_SCALE 2

	namespace XCam {
	CVFeatureMatchCluster::CVFeatureMatchCluster ()
	: CVFeatureMatch ()
	{
	}

	bool
	CVFeatureMatchCluster::calc_mean_offset (
	std::vector<cv::Point2f> &corner0, std::vector<cv::Point2f> &corner1,
	std::vector<uchar> &status, std::vector<float> &error,
	float &mean_offset_x, float &mean_offset_y,
	cv::InputOutputArray debug_img, cv::Size &img0_size, cv::Size &img1_size)
	{
	std::vector<std::vector<uint32_t>> clusters;
	std::vector<std::vector<cv::Point2f>> clusters_offsets;
	std::vector<uint32_t> valid_seeds (status.size ());
	std::vector<uint32_t> valid_corners (status.size ());

	for (uint32_t i = 0; i < status.size (); ++i) {
	if (!status[i] \|\| (error[i] > _config.max_track_error) \|\| corner1[i].x < 0.0f \|\| corner1[i].x > img0_size.width) {
	valid_corners[i] = 0;
	valid_seeds[i] = 0;
	} else {
	valid_corners[i] = 1;
	valid_seeds[i] = 1;
	}
	}

	float seed_x_offset = 0.0f;
	float seed_y_offset = 0.0f;

	std::vector<uint32_t> cluster (1);
	std::vector<cv::Point2f> cluster_offset (1);

	float thres = 8.0f;
	while (cluster.size() > 0) {
	cluster.clear ();
	cluster_offset.clear ();

	for (uint32_t i = 0; i < status.size (); ++i) {
	if (valid_seeds[i]) {
	seed_x_offset = corner1[i].x - corner0[i].x;
	seed_y_offset = corner1[i].y - corner0[i].y;
	cluster.push_back (i);
	cluster_offset.push_back (cv::Point2f(seed_x_offset, seed_y_offset));
	valid_corners[i] = 0;
	valid_seeds[i] = 0;
	break;
	}
	}

	if (cluster.size() > 0) {
	for (uint32_t i = 0; i < status.size (); ++i) {
	if (!valid_corners[i])
	continue;

	float x_offset = corner1[i].x - corner0[i].x;
	float y_offset = corner1[i].y - corner0[i].y;

	if (fabs (x_offset - seed_x_offset) > thres \|\| fabs (y_offset - seed_y_offset) > thres / 2.0f)
	continue;

	cluster.push_back (i);
	cluster_offset.push_back (cv::Point2f(x_offset, y_offset));
	valid_seeds[i] = 0;
	}

	clusters.push_back (cluster);
	clusters_offsets.push_back (cluster_offset);
	}
	}

	if (clusters_offsets.size () == 0)
	return false;

	uint32_t max_size = 0;
	uint32_t max_index = 0;

	for (uint32_t i = 0; i < clusters.size (); ++i) {
	if (clusters[i].size () > max_size) {
	max_size = clusters[i].size ();
	max_index = i;
	}
	}

	if (clusters_offsets[max_index].size () < (uint32_t)_config.min_corners)
	return false;

	float sum_x = 0.0f;
	float sum_y = 0.0f;
	for (uint32_t i = 0; i < clusters_offsets[max_index].size (); ++i) {
	sum_x += clusters_offsets[max_index][i].x;
	sum_y += clusters_offsets[max_index][i].y;
	}

	mean_offset_x = sum_x / clusters_offsets[max_index].size ();
	mean_offset_y = sum_y / clusters_offsets[max_index].size ();

	#if XCAM_CV_FM_DEBUG
	for (uint32_t i = 0; i < status.size (); ++i) {
	if(!status[i])
	continue;

	cv::Point start = cv::Point(corner0[i]) * XCAM_CV_OF_DRAW_SCALE;
	cv::circle (debug_img, start, 4, cv::Scalar(0), XCAM_CV_OF_DRAW_SCALE);
	cv::Point end = (cv::Point(corner1[i]) + cv::Point (img0_size.width, 0)) * XCAM_CV_OF_DRAW_SCALE;
	cv::line (debug_img, start, end, cv::Scalar(0), XCAM_CV_OF_DRAW_SCALE);
	}

	for (uint32_t i = 0; i < status.size (); ++i) {
	if (!status[i])
	continue;

	cv::Point start = cv::Point(corner0[i]) * XCAM_CV_OF_DRAW_SCALE;
	cv::circle (debug_img, start, 4, cv::Scalar(0), XCAM_CV_OF_DRAW_SCALE);
	if (error[i] > _config.max_track_error)
	continue;
	if (fabs(corner0[i].y - corner1[i].y) >= _config.max_valid_offset_y)
	continue;
	if (corner1[i].x < 0.0f \|\| corner1[i].x > img0_size.width)
	continue;

	cv::Point end = (cv::Point(corner1[i]) + cv::Point (img0_size.width, 0)) * XCAM_CV_OF_DRAW_SCALE;
	cv::line (debug_img, start, end, cv::Scalar(255), XCAM_CV_OF_DRAW_SCALE);
	}

	for (uint32_t i = 0; i < status.size (); ++i) {
	if(!status[i])
	continue;

	cv::Point start = (cv::Point(corner0[i]) + cv::Point (img0_size.width + img1_size.width, 0)) * XCAM_CV_OF_DRAW_SCALE;
	cv::circle (debug_img, start, 4, cv::Scalar(0), XCAM_CV_OF_DRAW_SCALE);
	cv::Point end = (cv::Point(corner1[i]) + cv::Point (2 * img0_size.width + img1_size.width, 0)) * XCAM_CV_OF_DRAW_SCALE;
	cv::line (debug_img, start, end, cv::Scalar(0), XCAM_CV_OF_DRAW_SCALE);
	}

	if (clusters.size () != 0)
	cluster = clusters[max_index];
	for (uint32_t i = 0; i < cluster.size (); ++i) {
	cv::Point start = (cv::Point(corner0[cluster[i]]) + cv::Point(img0_size.width + img1_size.width, 0)) * XCAM_CV_OF_DRAW_SCALE;
	cv::circle (debug_img, start, 4, cv::Scalar(0), XCAM_CV_OF_DRAW_SCALE);
	cv::Point end = (cv::Point(corner1[cluster[i]]) + cv::Point (2 * img0_size.width + img1_size.width, 0)) * XCAM_CV_OF_DRAW_SCALE;
	cv::line (debug_img, start, end, cv::Scalar(255), XCAM_CV_OF_DRAW_SCALE);
	}

	#endif

	XCAM_UNUSED (debug_img);
	XCAM_UNUSED (img0_size);
	XCAM_UNUSED (img1_size);

	clusters.clear ();
	clusters_offsets.clear ();

	return true;
	}

	void
	CVFeatureMatchCluster::calc_of_match_cluster (
	cv::InputArray image0, cv::InputArray image1,
	std::vector<cv::Point2f> &corner0, std::vector<cv::Point2f> &corner1,
	std::vector<uchar> &status, std::vector<float> &error,
	float &last_mean_offset_x, float &last_mean_offset_y,
	float &out_x_offset, float &out_y_offset)
	{
	cv::_InputOutputArray debug_img;
	cv::Size img0_size = image0.size ();
	cv::Size img1_size = image1.size ();
	XCAM_ASSERT (img0_size.height == image1.rows ());
	XCAM_UNUSED (image1);

	#if XCAM_CV_FM_DEBUG
	cv::Mat mat;
	cv::UMat umat;
	cv::Size size ((img0_size.width + img1_size.width) * 2, img0_size.height);

	if (image0.isUMat ()) {
	umat.create (size, image0.type ());
	debug_img = cv::_InputOutputArray (umat);

	image0.copyTo (umat (cv::Rect(0, 0, img0_size.width, img0_size.height)));
	image1.copyTo (umat (cv::Rect(img0_size.width, 0, img1_size.width, img1_size.height)));

	image0.copyTo (umat (cv::Rect(img0_size.width + img1_size.width, 0, img0_size.width, img0_size.height)));
	image1.copyTo (umat (cv::Rect(2 * img0_size.width + img1_size.width, 0, img1_size.width, img1_size.height)));
	umat.copyTo (debug_img);
	} else {
	mat.create (size, image0.type ());
	debug_img = cv::_InputOutputArray (mat);

	image0.copyTo (mat (cv::Rect(0, 0, img0_size.width, img0_size.height)));
	image1.copyTo (mat (cv::Rect(img0_size.width, 0, img1_size.width, img1_size.height)));

	image0.copyTo (mat (cv::Rect(img0_size.width + img1_size.width, 0, img0_size.width, img0_size.height)));
	image1.copyTo (mat (cv::Rect(2 * img0_size.width + img1_size.width, 0, img1_size.width, img1_size.height)));

	mat.copyTo (debug_img);
	}

	cv::Size scale_size = size * XCAM_CV_OF_DRAW_SCALE;
	cv::resize (debug_img, debug_img, scale_size, 0, 0);
	#endif

	float mean_offset_x = 0.0f;
	float mean_offset_y = 0.0f;
	bool ret = calc_mean_offset (corner0, corner1, status, error, mean_offset_x, mean_offset_y, debug_img, img0_size, img1_size);

	#if XCAM_CV_FM_DEBUG
	char file_name[256];
	std::snprintf (file_name, 256, "fm_optical_flow_%d_%d.jpg", _frame_num, _fm_idx);
	cv::imwrite (file_name, debug_img);
	#endif

	if (ret) {
	if (fabs (mean_offset_x - last_mean_offset_x) < _config.delta_mean_offset) {
	out_x_offset = out_x_offset * _config.offset_factor + mean_offset_x * (1.0f - _config.offset_factor);

	if (fabs (out_x_offset) > _config.max_adjusted_offset)
	out_x_offset = (out_x_offset > 0.0f) ? _config.max_adjusted_offset : (-_config.max_adjusted_offset);
	}

	if (fabs (mean_offset_y - last_mean_offset_y) < _config.delta_mean_offset) {
	out_y_offset = out_y_offset * _config.offset_factor + mean_offset_y * (1.0f - _config.offset_factor);

	if (fabs (out_y_offset) > _config.max_adjusted_offset)
	out_y_offset = (out_y_offset > 0.0f) ? _config.max_adjusted_offset : (-_config.max_adjusted_offset);
	}
	}

	last_mean_offset_x = mean_offset_x;
	last_mean_offset_y = mean_offset_y;
	}

	void
	CVFeatureMatchCluster::detect_and_match_cluster (
	cv::InputArray img_left, cv::InputArray img_right, Rect &crop_left, Rect &crop_right,
	float &mean_offset_x, float &mean_offset_y, float &x_offset, float &y_offset)
	{
	std::vector<float> err;
	std::vector<uchar> status;
	std::vector<cv::Point2f> corner_left, corner_right;
	cv::Ptr<cv::Feature2D> fast_detector;
	cv::Size win_size = cv::Size (21, 21);

	if (img_left.isUMat ())
	win_size = cv::Size (16, 16);

	fast_detector = cv::FastFeatureDetector::create (20, true);
	add_detected_data (img_left, fast_detector, corner_left);

	if (corner_left.empty ()) {
	return;
	}

	cv::calcOpticalFlowPyrLK (
	img_left, img_right, corner_left, corner_right, status, err, win_size, 3,
	cv::TermCriteria (cv::TermCriteria::COUNT + cv::TermCriteria::EPS, 30, 0.01f));

	calc_of_match_cluster (img_left, img_right, corner_left, corner_right,
	status, err, mean_offset_x, mean_offset_y, x_offset, y_offset);

	#if XCAM_CV_FM_DEBUG
	XCAM_LOG_INFO ("x_offset:%0.2f", x_offset);
	XCAM_LOG_INFO (
	"FeatureMatch(idx:%d): stiching area: left_area(pos_x:%d, width:%d), right_area(pos_x:%d, width:%d)",
	_fm_idx, crop_left.pos_x, crop_left.width, crop_right.pos_x, crop_right.width);
	#endif

	XCAM_UNUSED (crop_left);
	XCAM_UNUSED (crop_right);
	}

	void
	CVFeatureMatchCluster::optical_flow_feature_match (
	const SmartPtr<VideoBuffer> &left_buf, const SmartPtr<VideoBuffer> &right_buf,
	Rect &left_crop_rect, Rect &right_crop_rect, int dst_width)
	{
	#if HAVE_LIBCL
	cv::UMat left_umat, right_umat;
	if (!get_crop_image_umat (left_buf, left_crop_rect, left_umat, BufId0)
	\|\| !get_crop_image_umat (right_buf, right_crop_rect, right_umat, BufId1))
	return;

	cv::Mat left_mat = left_umat.getMat (cv::ACCESS_READ);
	cv::Mat right_mat = right_umat.getMat (cv::ACCESS_READ);
	#else
	cv::Mat left_mat, left_mat;
	if (!get_crop_image_mat (left_buf, left_crop_rect, left_mat)
	\|\| !get_crop_image_mat (right_buf, right_crop_rect, left_mat))
	return;
	#endif

	cv::_InputArray left_img = cv::_InputArray (left_mat);
	cv::_InputArray right_img = cv::_InputArray (right_mat);

	detect_and_match_cluster (left_img, right_img, left_crop_rect, right_crop_rect,
	_mean_offset, _mean_offset_y, _x_offset, _y_offset);

	#if XCAM_CV_FM_DEBUG
	XCAM_ASSERT (_fm_idx >= 0);

	char frame_str[64] = {'\0'};
	std::snprintf (frame_str, 64, "frame:%d", _frame_num);
	char fm_idx_str[64] = {'\0'};
	std::snprintf (fm_idx_str, 64, "fm_idx:%d", _fm_idx);

	char img_name[256] = {'\0'};
	std::snprintf (img_name, 256, "fm_in_stitch_area_%d_%d_0.jpg", _frame_num, _fm_idx);
	debug_write_image (left_buf, left_crop_rect, img_name, frame_str, fm_idx_str);

	std::snprintf (img_name, 256, "fm_in_stitch_area_%d_%d_1.jpg", _frame_num, _fm_idx);
	debug_write_image (right_buf, right_crop_rect, img_name, frame_str, fm_idx_str);

	XCAM_LOG_INFO ("FeatureMatch(idx:%d): frame number:%d done", _fm_idx, _frame_num);
	_frame_num++;
	#endif

	XCAM_UNUSED (dst_width);
	}

	}