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Commit 42fbfb9b authored by Vadim Pisarevsky's avatar Vadim Pisarevsky
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Merge pull request #7311 from fran6co:lsd

parents 43b60f46 8283ddb5
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Showing with 94 additions and 112 deletions
modules/imgproc/src/lsd.cpp
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......@@ -230,12 +230,9 @@ public:
private:
Mat image;
Mat_<double> scaled_image;
double *scaled_image_data;
Mat scaled_image;
Mat_<double> angles; // in rads
double *angles_data;
Mat_<double> modgrad;
double *modgrad_data;
Mat_<uchar> used;
int img_width;
......@@ -270,6 +267,8 @@ private:
struct coorlist* next;
};
std::vector<coorlist> list;
struct rect
{
double x1, y1, x2, y2; // first and second point of the line segment
......@@ -309,7 +308,7 @@ private:
* @param list Return: Vector of coordinate points that are pseudo ordered by magnitude.
* Pixels would be ordered by norm value, up to a precision given by max_grad/n_bins.
*/
void ll_angle(const double& threshold, const unsigned int& n_bins, std::vector<coorlist>& list);
void ll_angle(const double& threshold, const unsigned int& n_bins);
/**
* Grow a region starting from point s with a defined precision,
......@@ -317,31 +316,29 @@ 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;
/**
......@@ -350,14 +347,14 @@ 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);
/**
......@@ -383,7 +380,7 @@ private:
* Is the point at place 'address' aligned to angle theta, up to precision 'prec'?
* @return Whether the point is aligned.
*/
bool isAligned(const int& address, const double& theta, const double& prec) const;
bool isAligned(int x, int y, const double& theta, const double& prec) const;
};
/////////////////////////////////////////////////////////////////////////////////////////
......@@ -414,11 +411,8 @@ void LineSegmentDetectorImpl::detect(InputArray _image, OutputArray _lines,
{
CV_INSTRUMENT_REGION()
Mat_<double> img = _image.getMat();
CV_Assert(!img.empty() && img.channels() == 1);
// Convert image to double
img.convertTo(image, CV_64FC1);
image = _image.getMat();
CV_Assert(!image.empty() && image.type() == CV_8UC1);
std::vector<Vec4f> lines;
std::vector<double> w, p, n;
......@@ -446,7 +440,6 @@ void LineSegmentDetectorImpl::flsd(std::vector<Vec4f>& lines,
const double p = ANG_TH / 180;
const double rho = QUANT / sin(prec); // gradient magnitude threshold
std::vector<coorlist> list;
if(SCALE != 1)
{
Mat gaussian_img;
......@@ -457,45 +450,43 @@ void LineSegmentDetectorImpl::flsd(std::vector<Vec4f>& lines,
GaussianBlur(image, gaussian_img, ksize, sigma);
// Scale image to needed size
resize(gaussian_img, scaled_image, Size(), SCALE, SCALE);
ll_angle(rho, N_BINS, list);
ll_angle(rho, N_BINS);
}
else
{
scaled_image = image;
ll_angle(rho, N_BINS, list);
ll_angle(rho, N_BINS);
}
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
unsigned int ls_count = 0;
for(size_t i = 0, list_size = list.size(); i < list_size; ++i)
{
unsigned int adx = list[i].p.x + list[i].p.y * img_width;
if((used.ptr()[adx] == NOTUSED) && (angles_data[adx] != NOTDEF))
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)
{
......@@ -505,7 +496,6 @@ void LineSegmentDetectorImpl::flsd(std::vector<Vec4f>& lines,
}
}
// Found new line
++ls_count;
// Add the offset
rec.x1 += 0.5; rec.y1 += 0.5;
......@@ -524,29 +514,17 @@ void LineSegmentDetectorImpl::flsd(std::vector<Vec4f>& lines,
if(w_needed) widths.push_back(rec.width);
if(p_needed) precisions.push_back(rec.p);
if(n_needed && doRefine >= LSD_REFINE_ADV) nfas.push_back(log_nfa);
// //Add the linesID to the region on the image
// for(unsigned int el = 0; el < reg_size; el++)
// {
// region.data[reg[i].x + reg[i].y * width] = ls_count;
// }
}
}
}
void LineSegmentDetectorImpl::ll_angle(const double& threshold,
const unsigned int& n_bins,
std::vector<coorlist>& list)
const unsigned int& n_bins)
{
//Initialize data
angles = Mat_<double>(scaled_image.size());
modgrad = Mat_<double>(scaled_image.size());
angles_data = angles.ptr<double>(0);
modgrad_data = modgrad.ptr<double>(0);
scaled_image_data = scaled_image.ptr<double>(0);
img_width = scaled_image.cols;
img_height = scaled_image.rows;
......@@ -555,30 +533,30 @@ void LineSegmentDetectorImpl::ll_angle(const double& threshold,
angles.col(img_width - 1).setTo(NOTDEF);
// Computing gradient for remaining pixels
CV_Assert(scaled_image.isContinuous() &&
modgrad.isContinuous() &&
angles.isContinuous()); // Accessing image data linearly
double max_grad = -1;
for(int y = 0; y < img_height - 1; ++y)
{
for(int addr = y * img_width, addr_end = addr + img_width - 1; addr < addr_end; ++addr)
const uchar* scaled_image_row = scaled_image.ptr<uchar>(y);
const uchar* next_scaled_image_row = scaled_image.ptr<uchar>(y+1);
double* angles_row = angles.ptr<double>(y);
double* modgrad_row = modgrad.ptr<double>(y);
for(int x = 0; x < img_width-1; ++x)
{
double DA = scaled_image_data[addr + img_width + 1] - scaled_image_data[addr];
double BC = scaled_image_data[addr + 1] - scaled_image_data[addr + img_width];
double gx = DA + BC; // gradient x component
double gy = DA - BC; // gradient y component
double norm = std::sqrt((gx * gx + gy * gy) / 4); // gradient norm
int DA = next_scaled_image_row[x + 1] - scaled_image_row[x];
int BC = scaled_image_row[x + 1] - next_scaled_image_row[x];
int gx = DA + BC; // gradient x component
int gy = DA - BC; // gradient y component
double norm = std::sqrt((gx * gx + gy * gy) / 4.0); // gradient norm
modgrad_data[addr] = norm; // store gradient
modgrad_row[x] = norm; // store gradient
if (norm <= threshold) // norm too small, gradient no defined
{
angles_data[addr] = NOTDEF;
angles_row[x] = NOTDEF;
}
else
{
angles_data[addr] = fastAtan2(float(gx), float(-gy)) * DEG_TO_RADS; // gradient angle computation
angles_row[x] = fastAtan2(float(gx), float(-gy)) * DEG_TO_RADS; // gradient angle computation
if (norm > max_grad) { max_grad = norm; }
}
......@@ -586,7 +564,7 @@ void LineSegmentDetectorImpl::ll_angle(const double& threshold,
}
// Compute histogram of gradient values
list = std::vector<coorlist>(img_width * img_height);
list.resize(img_width * img_height);
std::vector<coorlist*> range_s(n_bins);
std::vector<coorlist*> range_e(n_bins);
unsigned int count = 0;
......@@ -594,11 +572,11 @@ void LineSegmentDetectorImpl::ll_angle(const double& threshold,
for(int y = 0; y < img_height - 1; ++y)
{
const double* norm = modgrad_data + y * img_width;
for(int x = 0; x < img_width - 1; ++x, ++norm)
const double* modgrad_row = modgrad.ptr<double>(y);
for(int x = 0; x < img_width - 1; ++x)
{
// Store the point in the right bin according to its norm
int i = int((*norm) * bin_coef);
int i = int(modgrad_row[x] * bin_coef);
if(!range_e[i])
{
range_e[i] = range_s[i] = &list[count];
......@@ -635,46 +613,51 @@ 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;
int addr = s.x + s.y * img_width;
reg[0].used = used.ptr() + addr;
reg_angle = angles_data[addr];
reg[0].angle = reg_angle;
reg[0].modgrad = modgrad_data[addr];
RegionPoint seed;
seed.x = s.x;
seed.y = s.y;
seed.used = &used.at<uchar>(s);
reg_angle = angles.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);
int yy_min = std::max(rpoint.y - 1, 0), yy_max = std::min(rpoint.y + 1, img_height - 1);
for(int yy = yy_min; yy <= yy_max; ++yy)
{
int c_addr = xx_min + yy * img_width;
for(int xx = xx_min; xx <= xx_max; ++xx, ++c_addr)
uchar* used_row = used.ptr<uchar>(yy);
const double* angles_row = angles.ptr<double>(yy);
const double* modgrad_row = modgrad.ptr<double>(yy);
for(int xx = xx_min; xx <= xx_max; ++xx)
{
if((used.ptr()[c_addr] != USED) &&
(isAligned(c_addr, reg_angle, prec)))
uchar& is_used = used_row[xx];
if(is_used != USED &&
(isAligned(xx, yy, reg_angle, prec)))
{
const double& angle = angles_row[xx];
// Add point
used.ptr()[c_addr] = USED;
RegionPoint& region_point = reg[reg_size];
is_used = USED;
RegionPoint region_point;
region_point.x = xx;
region_point.y = yy;
region_point.used = &(used.ptr()[c_addr]);
region_point.modgrad = modgrad_data[c_addr];
const double& angle = angles_data[c_addr];
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));
......@@ -687,11 +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;
......@@ -706,14 +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;
......@@ -745,7 +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;
......@@ -753,7 +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;
......@@ -783,10 +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; }
......@@ -797,7 +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)
......@@ -814,16 +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
{
......@@ -831,7 +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
......@@ -845,25 +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);
}
......@@ -981,7 +964,7 @@ double LineSegmentDetectorImpl::rect_nfa(const rect& rec) const
double dyhw = rec.dy * half_width;
double dxhw = rec.dx * half_width;
std::vector<edge> ordered_x(4);
edge ordered_x[4];
edge* min_y = &ordered_x[0];
edge* max_y = &ordered_x[0]; // Will be used for loop range
......@@ -990,7 +973,7 @@ double LineSegmentDetectorImpl::rect_nfa(const rect& rec) const
ordered_x[2].p.x = int(rec.x2 + dyhw); ordered_x[2].p.y = int(rec.y2 - dxhw); ordered_x[2].taken = false;
ordered_x[3].p.x = int(rec.x1 + dyhw); ordered_x[3].p.y = int(rec.y1 - dxhw); ordered_x[3].taken = false;
std::sort(ordered_x.begin(), ordered_x.end(), AsmallerB_XoverY);
std::sort(ordered_x, ordered_x + 4, AsmallerB_XoverY);
// Find min y. And mark as taken. find max y.
for(unsigned int i = 1; i < 4; ++i)
......@@ -1075,13 +1058,12 @@ double LineSegmentDetectorImpl::rect_nfa(const rect& rec) const
{
if (y < 0 || y >= img_height) continue;
int adx = y * img_width + int(left_x);
for(int x = int(left_x); x <= int(right_x); ++x, ++adx)
for(int x = int(left_x); x <= int(right_x); ++x)
{
if (x < 0 || x >= img_width) continue;
++total_pts;
if(isAligned(adx, rec.theta, rec.prec))
if(isAligned(x, y, rec.theta, rec.prec))
{
++alg_pts;
}
......@@ -1135,10 +1117,10 @@ double LineSegmentDetectorImpl::nfa(const int& n, const int& k, const double& p)
return -log10(bin_tail) - LOG_NT;
}
inline bool LineSegmentDetectorImpl::isAligned(const int& address, const double& theta, const double& prec) const
inline bool LineSegmentDetectorImpl::isAligned(int x, int y, const double& theta, const double& prec) const
{
if(address < 0) { return false; }
const double& a = angles_data[address];
if(x < 0 || y < 0 || x >= angles.cols || y >= angles.rows) { return false; }
const double& a = angles.at<double>(y, x);
if(a == NOTDEF) { return false; }
// It is assumed that 'theta' and 'a' are in the range [-pi,pi]
......
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