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LSD: Avoid pre allocating a big region, std::vector allocations is quite expensive

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This commit is contained in:
Francisco Facioni 2016-09-20 09:36:09 +01:00
parent a12207c3ad
commit ef6b696446
1 changed files with 46 additions and 46 deletions
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92
modules/imgproc/src/lsd.cpp
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@ -314,31 +314,29 @@ private:
*
* @param s Starting point for the region.
* @param reg Return: Vector of points, that are part of the region
* @param reg_size Return: The size of the region.
* @param reg_angle Return: The mean angle of the region.
* @param prec The precision by which each region angle should be aligned to the mean.
*/
void region_grow(const Point2i& s, std::vector<RegionPoint>& reg,
int& reg_size, double& reg_angle, const double& prec);
double& reg_angle, const double& prec);
/**
* Finds the bounding rotated rectangle of a region.
*
* @param reg The region of points, from which the rectangle to be constructed from.
* @param reg_size The number of points in the region.
* @param reg_angle The mean angle of the region.
* @param prec The precision by which points were found.
* @param p Probability of a point with angle within 'prec'.
* @param rec Return: The generated rectangle.
*/
void region2rect(const std::vector<RegionPoint>& reg, const int reg_size, const double reg_angle,
void region2rect(const std::vector<RegionPoint>& reg, const double reg_angle,
const double prec, const double p, rect& rec) const;
/**
* Compute region's angle as the principal inertia axis of the region.
* @return Regions angle.
*/
double get_theta(const std::vector<RegionPoint>& reg, const int& reg_size, const double& x,
double get_theta(const std::vector<RegionPoint>& reg, const double& x,
const double& y, const double& reg_angle, const double& prec) const;
/**
@ -347,14 +345,14 @@ private:
* estimated angle tolerance. If this fails to produce a rectangle with the right density of region points,
* 'reduce_region_radius' is called to try to satisfy this condition.
*/
bool refine(std::vector<RegionPoint>& reg, int& reg_size, double reg_angle,
bool refine(std::vector<RegionPoint>& reg, double reg_angle,
const double prec, double p, rect& rec, const double& density_th);
/**
* Reduce the region size, by elimination the points far from the starting point, until that leads to
* rectangle with the right density of region points or to discard the region if too small.
*/
bool reduce_region_radius(std::vector<RegionPoint>& reg, int& reg_size, double reg_angle,
bool reduce_region_radius(std::vector<RegionPoint>& reg, double reg_angle,
const double prec, double p, rect& rec, double density, const double& density_th);
/**
@ -460,12 +458,12 @@ void LineSegmentDetectorImpl::flsd(std::vector<Vec4f>& lines,
}
LOG_NT = 5 * (log10(double(img_width)) + log10(double(img_height))) / 2 + log10(11.0);
const int min_reg_size = int(-LOG_NT/log10(p)); // minimal number of points in region that can give a meaningful event
const size_t min_reg_size = size_t(-LOG_NT/log10(p)); // minimal number of points in region that can give a meaningful event
// // Initialize region only when needed
// Mat region = Mat::zeros(scaled_image.size(), CV_8UC1);
used = Mat_<uchar>::zeros(scaled_image.size()); // zeros = NOTUSED
std::vector<RegionPoint> reg(img_width * img_height);
std::vector<RegionPoint> reg;
// Search for line segments
for(size_t i = 0, list_size = list.size(); i < list_size; ++i)
@ -473,22 +471,21 @@ void LineSegmentDetectorImpl::flsd(std::vector<Vec4f>& lines,
const Point2i& point = list[i].p;
if((used.at<uchar>(point) == NOTUSED) && (angles.at<double>(point) != NOTDEF))
{
int reg_size;
double reg_angle;
region_grow(list[i].p, reg, reg_size, reg_angle, prec);
region_grow(list[i].p, reg, reg_angle, prec);
// Ignore small regions
if(reg_size < min_reg_size) { continue; }
if(reg.size() < min_reg_size) { continue; }
// Construct rectangular approximation for the region
rect rec;
region2rect(reg, reg_size, reg_angle, prec, p, rec);
region2rect(reg, reg_angle, prec, p, rec);
double log_nfa = -1;
if(doRefine > LSD_REFINE_NONE)
{
// At least REFINE_STANDARD lvl.
if(!refine(reg, reg_size, reg_angle, prec, p, rec, DENSITY_TH)) { continue; }
if(!refine(reg, reg_angle, prec, p, rec, DENSITY_TH)) { continue; }
if(doRefine >= LSD_REFINE_ADV)
{
@ -616,23 +613,26 @@ void LineSegmentDetectorImpl::ll_angle(const double& threshold,
}
void LineSegmentDetectorImpl::region_grow(const Point2i& s, std::vector<RegionPoint>& reg,
int& reg_size, double& reg_angle, const double& prec)
double& reg_angle, const double& prec)
{
reg.clear();
// Point to this region
reg_size = 1;
reg[0].x = s.x;
reg[0].y = s.y;
reg[0].used = &used.at<uchar>(s);
RegionPoint seed;
seed.x = s.x;
seed.y = s.y;
seed.used = &used.at<uchar>(s);
reg_angle = angles.at<double>(s);
reg[0].angle = reg_angle;
reg[0].modgrad = modgrad.at<double>(s);
seed.angle = reg_angle;
seed.modgrad = modgrad.at<double>(s);
reg.push_back(seed);
float sumdx = float(std::cos(reg_angle));
float sumdy = float(std::sin(reg_angle));
*reg[0].used = USED;
*seed.used = USED;
//Try neighboring regions
for(int i = 0; i < reg_size; ++i)
for (size_t i = 0;i<reg.size();i++)
{
const RegionPoint& rpoint = reg[i];
int xx_min = std::max(rpoint.x - 1, 0), xx_max = std::min(rpoint.x + 1, img_width - 1);
@ -651,13 +651,13 @@ void LineSegmentDetectorImpl::region_grow(const Point2i& s, std::vector<RegionPo
const double& angle = angles_row[xx];
// Add point
is_used = USED;
RegionPoint& region_point = reg[reg_size];
RegionPoint region_point;
region_point.x = xx;
region_point.y = yy;
region_point.used = &is_used;
region_point.modgrad = modgrad_row[xx];
region_point.angle = angle;
++reg_size;
reg.push_back(region_point);
// Update region's angle
sumdx += cos(float(angle));
@ -670,11 +670,11 @@ void LineSegmentDetectorImpl::region_grow(const Point2i& s, std::vector<RegionPo
}
}
void LineSegmentDetectorImpl::region2rect(const std::vector<RegionPoint>& reg, const int reg_size,
void LineSegmentDetectorImpl::region2rect(const std::vector<RegionPoint>& reg,
const double reg_angle, const double prec, const double p, rect& rec) const
{
double x = 0, y = 0, sum = 0;
for(int i = 0; i < reg_size; ++i)
for(size_t i = 0; i < reg.size(); ++i)
{
const RegionPoint& pnt = reg[i];
const double& weight = pnt.modgrad;
@ -689,14 +689,14 @@ void LineSegmentDetectorImpl::region2rect(const std::vector<RegionPoint>& reg, c
x /= sum;
y /= sum;
double theta = get_theta(reg, reg_size, x, y, reg_angle, prec);
double theta = get_theta(reg, x, y, reg_angle, prec);
// Find length and width
double dx = cos(theta);
double dy = sin(theta);
double l_min = 0, l_max = 0, w_min = 0, w_max = 0;
for(int i = 0; i < reg_size; ++i)
for(size_t i = 0; i < reg.size(); ++i)
{
double regdx = double(reg[i].x) - x;
double regdy = double(reg[i].y) - y;
@ -728,7 +728,7 @@ void LineSegmentDetectorImpl::region2rect(const std::vector<RegionPoint>& reg, c
if(rec.width < 1.0) rec.width = 1.0;
}
double LineSegmentDetectorImpl::get_theta(const std::vector<RegionPoint>& reg, const int& reg_size, const double& x,
double LineSegmentDetectorImpl::get_theta(const std::vector<RegionPoint>& reg, const double& x,
const double& y, const double& reg_angle, const double& prec) const
{
double Ixx = 0.0;
@ -736,7 +736,7 @@ double LineSegmentDetectorImpl::get_theta(const std::vector<RegionPoint>& reg, c
double Ixy = 0.0;
// Compute inertia matrix
for(int i = 0; i < reg_size; ++i)
for(size_t i = 0; i < reg.size(); ++i)
{
const double& regx = reg[i].x;
const double& regy = reg[i].y;
@ -766,10 +766,10 @@ double LineSegmentDetectorImpl::get_theta(const std::vector<RegionPoint>& reg, c
return theta;
}
bool LineSegmentDetectorImpl::refine(std::vector<RegionPoint>& reg, int& reg_size, double reg_angle,
bool LineSegmentDetectorImpl::refine(std::vector<RegionPoint>& reg, double reg_angle,
const double prec, double p, rect& rec, const double& density_th)
{
double density = double(reg_size) / (dist(rec.x1, rec.y1, rec.x2, rec.y2) * rec.width);
double density = double(reg.size()) / (dist(rec.x1, rec.y1, rec.x2, rec.y2) * rec.width);
if (density >= density_th) { return true; }
@ -780,7 +780,7 @@ bool LineSegmentDetectorImpl::refine(std::vector<RegionPoint>& reg, int& reg_siz
double sum = 0, s_sum = 0;
int n = 0;
for (int i = 0; i < reg_size; ++i)
for (size_t i = 0; i < reg.size(); ++i)
{
*(reg[i].used) = NOTUSED;
if (dist(xc, yc, reg[i].x, reg[i].y) < rec.width)
@ -797,16 +797,16 @@ bool LineSegmentDetectorImpl::refine(std::vector<RegionPoint>& reg, int& reg_siz
double tau = 2.0 * sqrt((s_sum - 2.0 * mean_angle * sum) / double(n) + mean_angle * mean_angle);
// Try new region
region_grow(Point(reg[0].x, reg[0].y), reg, reg_size, reg_angle, tau);
region_grow(Point(reg[0].x, reg[0].y), reg, reg_angle, tau);
if (reg_size < 2) { return false; }
if (reg.size() < 2) { return false; }
region2rect(reg, reg_size, reg_angle, prec, p, rec);
density = double(reg_size) / (dist(rec.x1, rec.y1, rec.x2, rec.y2) * rec.width);
region2rect(reg, reg_angle, prec, p, rec);
density = double(reg.size()) / (dist(rec.x1, rec.y1, rec.x2, rec.y2) * rec.width);
if (density < density_th)
{
return reduce_region_radius(reg, reg_size, reg_angle, prec, p, rec, density, density_th);
return reduce_region_radius(reg, reg_angle, prec, p, rec, density, density_th);
}
else
{
@ -814,7 +814,7 @@ bool LineSegmentDetectorImpl::refine(std::vector<RegionPoint>& reg, int& reg_siz
}
}
bool LineSegmentDetectorImpl::reduce_region_radius(std::vector<RegionPoint>& reg, int& reg_size, double reg_angle,
bool LineSegmentDetectorImpl::reduce_region_radius(std::vector<RegionPoint>& reg, double reg_angle,
const double prec, double p, rect& rec, double density, const double& density_th)
{
// Compute region's radius
@ -828,25 +828,25 @@ bool LineSegmentDetectorImpl::reduce_region_radius(std::vector<RegionPoint>& reg
{
radSq *= 0.75*0.75; // Reduce region's radius to 75% of its value
// Remove points from the region and update 'used' map
for(int i = 0; i < reg_size; ++i)
for (size_t i = 0; i < reg.size(); ++i)
{
if(distSq(xc, yc, double(reg[i].x), double(reg[i].y)) > radSq)
{
// Remove point from the region
*(reg[i].used) = NOTUSED;
std::swap(reg[i], reg[reg_size - 1]);
--reg_size;
std::swap(reg[i], reg[reg.size() - 1]);
reg.pop_back();
--i; // To avoid skipping one point
}
}
if(reg_size < 2) { return false; }
if(reg.size() < 2) { return false; }
// Re-compute rectangle
region2rect(reg, reg_size ,reg_angle, prec, p, rec);
region2rect(reg ,reg_angle, prec, p, rec);
// Re-compute region points density
density = double(reg_size) /
density = double(reg.size()) /
(dist(rec.x1, rec.y1, rec.x2, rec.y2) * rec.width);
}