From 7e4769a04700315b67d97ca9b40ce926f6cfc3b2 Mon Sep 17 00:00:00 2001 From: Alexey Spizhevoy Date: Wed, 11 May 2011 05:28:55 +0000 Subject: [PATCH] reduced memory requirements for multi-band blending --- modules/stitching/blenders.cpp | 129 ++++++++++++++++++--------------- modules/stitching/blenders.hpp | 4 +- 2 files changed, 73 insertions(+), 60 deletions(-) diff --git a/modules/stitching/blenders.cpp b/modules/stitching/blenders.cpp index e3096e773d..4ca8fc38ec 100644 --- a/modules/stitching/blenders.cpp +++ b/modules/stitching/blenders.cpp @@ -1,4 +1,5 @@ #include +#include #include "blenders.hpp" #include "util.hpp" @@ -101,64 +102,70 @@ Point MultiBandBlender::blend(const vector &src, const vector &corne { CV_Assert(src.size() == corners.size() && src.size() == masks.size()); const int num_images = src.size(); + const int img_type = src[0].type(); Rect dst_roi = resultRoi(src, corners); - - vector src_(num_images); - vector corners_(num_images); - vector masks_(num_images); - - // TODO avoid creating extra border - for (int i = 0; i < num_images; ++i) - { - copyMakeBorder(src[i], src_[i], - corners[i].y - dst_roi.y, dst_roi.br().y - corners[i].y - src[i].rows, - corners[i].x - dst_roi.x, dst_roi.br().x - corners[i].x - src[i].cols, - BORDER_REFLECT); - copyMakeBorder(masks[i], masks_[i], - corners[i].y - dst_roi.y, dst_roi.br().y - corners[i].y - src[i].rows, - corners[i].x - dst_roi.x, dst_roi.br().x - corners[i].x - src[i].cols, - BORDER_CONSTANT); - corners_[i] = Point(0, 0); - } - - Mat weight_map; - vector src_pyr_gauss; - vector< vector > src_pyr_laplace(num_images); - vector< vector > weight_pyr_gauss(num_images); - - // Compute all pyramids - for (int i = 0; i < num_images; ++i) - { - createGaussPyr(src_[i], num_bands_, src_pyr_gauss); - createLaplacePyr(src_pyr_gauss, src_pyr_laplace[i]); - - masks_[i].convertTo(weight_map, CV_32F, 1. / 255.); - createGaussPyr(weight_map, num_bands_, weight_pyr_gauss[i]); - } - computeResultMask(masks, corners, dst_mask); - Mat dst_level_weight; vector dst_pyr_laplace(num_bands_ + 1); - vector src_pyr_slice(num_images); - vector weight_pyr_slice(num_images); + dst_pyr_laplace[0].create(dst_roi.size(), img_type); + dst_pyr_laplace[0].setTo(Scalar::all(0)); - // Blend pyramids - for (int level_id = 0; level_id <= num_bands_; ++level_id) + vector dst_band_weights(num_bands_ + 1); + dst_band_weights[0].create(dst_roi.size(), CV_32F); + dst_band_weights[0].setTo(0); + + for (int i = 1; i <= num_bands_; ++i) { - for (int i = 0; i < num_images; ++i) - { - src_pyr_slice[i] = src_pyr_laplace[i][level_id]; - weight_pyr_slice[i] = weight_pyr_gauss[i][level_id]; - } - blendLinear(src_pyr_slice, corners_, weight_pyr_slice, - dst_pyr_laplace[level_id], dst_level_weight); + dst_pyr_laplace[i].create((dst_pyr_laplace[i - 1].rows + 1) / 2, + (dst_pyr_laplace[i - 1].cols + 1) / 2, img_type); + dst_pyr_laplace[i].setTo(Scalar::all(0)); + + dst_band_weights[i].create((dst_band_weights[i - 1].rows + 1) / 2, + (dst_band_weights[i - 1].cols + 1) / 2, CV_32F); + dst_band_weights[i].setTo(0); } + for (int img_idx = 0; img_idx < num_images; ++img_idx) + { + int top = corners[img_idx].y - dst_roi.y; + int bottom = dst_roi.br().y - corners[img_idx].y - src[img_idx].rows; + int left = corners[img_idx].x - dst_roi.x; + int right = dst_roi.br().x - corners[img_idx].x - src[img_idx].cols; + + Mat big_src; + copyMakeBorder(src[img_idx], big_src, top, bottom, left, right, BORDER_REFLECT); + vector src_pyr_gauss; + vector src_pyr_laplace; + createGaussPyr(big_src, num_bands_, src_pyr_gauss); + createLaplacePyr(src_pyr_gauss, src_pyr_laplace); + + Mat big_mask; + copyMakeBorder(masks[img_idx], big_mask, top, bottom, left, right, BORDER_CONSTANT); + Mat weight_map; + big_mask.convertTo(weight_map, CV_32F, 1./255.); + vector weight_pyr_gauss; + createGaussPyr(weight_map, num_bands_, weight_pyr_gauss); + + for (int band_idx = 0; band_idx <= num_bands_; ++band_idx) + { + for (int y = 0; y < dst_pyr_laplace[band_idx].rows; ++y) + { + const Point3f* src_row = src_pyr_laplace[band_idx].ptr(y); + const float* weight_row = weight_pyr_gauss[band_idx].ptr(y); + Point3f* dst_row = dst_pyr_laplace[band_idx].ptr(y); + for (int x = 0; x < dst_pyr_laplace[band_idx].cols; ++x) + dst_row[x] += src_row[x] * weight_row[x]; + } + dst_band_weights[band_idx] += weight_pyr_gauss[band_idx]; + } + } + + for (int band_idx = 0; band_idx <= num_bands_; ++band_idx) + normalize(dst_band_weights[band_idx], dst_pyr_laplace[band_idx]); + restoreImageFromLaplacePyr(dst_pyr_laplace); dst = dst_pyr_laplace[0]; - return dst_roi.tl(); } @@ -250,23 +257,27 @@ Point blendLinear(const vector &src, const vector &corners, const ve } } - // Normalize sums - for (int y = 0; y < dst.rows; ++y) - { - Point3f *dst_row = dst.ptr(y); - float *dst_weight_row = dst_weight.ptr(y); - - for (int x = 0; x < dst.cols; ++x) - { - dst_weight_row[x] += WEIGHT_EPS; - dst_row[x] *= 1.f / dst_weight_row[x]; - } - } + normalize(dst_weight, dst); return dst_roi.tl(); } +void normalize(const Mat& weight, Mat& src) +{ + CV_Assert(weight.type() == CV_32F); + CV_Assert(src.type() == CV_32FC3); + for (int y = 0; y < src.rows; ++y) + { + Point3f *row = src.ptr(y); + const float *weight_row = weight.ptr(y); + + for (int x = 0; x < src.cols; ++x) + row[x] *= 1.f / (weight_row[x] + WEIGHT_EPS); + } +} + + void createWeightMap(const Mat &mask, float sharpness, Mat &weight) { CV_Assert(mask.type() == CV_8U); diff --git a/modules/stitching/blenders.hpp b/modules/stitching/blenders.hpp index b9a143951f..a2151b647a 100644 --- a/modules/stitching/blenders.hpp +++ b/modules/stitching/blenders.hpp @@ -59,13 +59,15 @@ cv::Point computeResultMask(const std::vector &masks, const std::vector cv::Point blendLinear(const std::vector &src, const std::vector &corners, const std::vector &weights, cv::Mat& dst, cv::Mat& dst_weight); +void normalize(const cv::Mat& weight, cv::Mat& src); + void createWeightMap(const cv::Mat& mask, float sharpness, cv::Mat& weight); void createGaussPyr(const cv::Mat& img, int num_layers, std::vector& pyr); void createLaplacePyr(const std::vector& pyr_gauss, std::vector& pyr_laplace); -// Restores source image in-place. Result will be in pyr[0]. +// Restores source image in-place. Result will be stored in pyr[0]. void restoreImageFromLaplacePyr(std::vector& pyr); #endif // __OPENCV_BLENDERS_HPP__