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diff --git a/ml/dlib/dlib/image_keypoint/hog.h b/ml/dlib/dlib/image_keypoint/hog.h
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+++ b/ml/dlib/dlib/image_keypoint/hog.h
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+// Copyright (C) 2010 Davis E. King (davis@dlib.net)
+// License: Boost Software License See LICENSE.txt for the full license.
+#ifndef DLIB_HoG_Hh_
+#define DLIB_HoG_Hh_
+
+#include "hog_abstract.h"
+#include "../algs.h"
+#include "../matrix.h"
+#include "../array2d.h"
+#include "../geometry.h"
+#include <cmath>
+
+namespace dlib
+{
+ enum
+ {
+ hog_no_interpolation,
+ hog_angle_interpolation,
+ hog_full_interpolation,
+ hog_signed_gradient,
+ hog_unsigned_gradient
+ };
+
+ template <
+ unsigned long cell_size_,
+ unsigned long block_size_,
+ unsigned long cell_stride_,
+ unsigned long num_orientation_bins_,
+ int gradient_type_,
+ int interpolation_type_
+ >
+ class hog_image : noncopyable
+ {
+ COMPILE_TIME_ASSERT(cell_size_ > 1);
+ COMPILE_TIME_ASSERT(block_size_ > 0);
+ COMPILE_TIME_ASSERT(cell_stride_ > 0);
+ COMPILE_TIME_ASSERT(num_orientation_bins_ > 0);
+
+ COMPILE_TIME_ASSERT( gradient_type_ == hog_signed_gradient ||
+ gradient_type_ == hog_unsigned_gradient);
+
+ COMPILE_TIME_ASSERT( interpolation_type_ == hog_no_interpolation ||
+ interpolation_type_ == hog_angle_interpolation ||
+ interpolation_type_ == hog_full_interpolation );
+
+
+ public:
+
+ const static unsigned long cell_size = cell_size_;
+ const static unsigned long block_size = block_size_;
+ const static unsigned long cell_stride = cell_stride_;
+ const static unsigned long num_orientation_bins = num_orientation_bins_;
+ const static int gradient_type = gradient_type_;
+ const static int interpolation_type = interpolation_type_;
+
+ const static long min_size = cell_size*block_size+2;
+
+ typedef matrix<double, block_size*block_size*num_orientation_bins, 1> descriptor_type;
+
+ hog_image (
+ ) :
+ num_block_rows(0),
+ num_block_cols(0)
+ {}
+
+ void clear (
+ )
+ {
+ num_block_rows = 0;
+ num_block_cols = 0;
+ hist_cells.clear();
+ }
+
+ void copy_configuration (
+ const hog_image&
+ ){}
+
+ template <
+ typename image_type
+ >
+ inline void load (
+ const image_type& img
+ )
+ {
+ COMPILE_TIME_ASSERT( pixel_traits<typename image_traits<image_type>::pixel_type>::has_alpha == false );
+ load_impl(mat(img));
+ }
+
+ inline void unload(
+ ) { clear(); }
+
+ inline size_t size (
+ ) const { return static_cast<size_t>(nr()*nc()); }
+
+ inline long nr (
+ ) const { return num_block_rows; }
+
+ inline long nc (
+ ) const { return num_block_cols; }
+
+ long get_num_dimensions (
+ ) const
+ {
+ return block_size*block_size*num_orientation_bins;
+ }
+
+ inline const descriptor_type& operator() (
+ long row,
+ long col
+ ) const
+ {
+ // make sure requires clause is not broken
+ DLIB_ASSERT( 0 <= row && row < nr() &&
+ 0 <= col && col < nc(),
+ "\t descriptor_type hog_image::operator()()"
+ << "\n\t invalid row or col argument"
+ << "\n\t row: " << row
+ << "\n\t col: " << col
+ << "\n\t nr(): " << nr()
+ << "\n\t nc(): " << nc()
+ << "\n\t this: " << this
+ );
+
+ row *= cell_stride;
+ col *= cell_stride;
+ ++row;
+ ++col;
+
+ int feat = 0;
+ for (unsigned long r = 0; r < block_size; ++r)
+ {
+ for (unsigned long c = 0; c < block_size; ++c)
+ {
+ for (unsigned long i = 0; i < num_orientation_bins; ++i)
+ {
+ des(feat++) = hist_cells[row+r][col+c].values[i];
+ }
+ }
+ }
+
+ des /= length(des) + 1e-8;
+
+ return des;
+ }
+
+ const rectangle get_block_rect (
+ long row,
+ long col
+ ) const
+ {
+ row *= cell_stride;
+ col *= cell_stride;
+
+ row *= cell_size;
+ col *= cell_size;
+
+ // do this to account for the 1 pixel padding we use all around the image
+ ++row;
+ ++col;
+
+ return rectangle(col, row, col+cell_size*block_size-1, row+cell_size*block_size-1);
+ }
+
+ const point image_to_feat_space (
+ const point& p
+ ) const
+ {
+
+ const long half_block = block_size/2;
+ if ((block_size%2) == 0)
+ {
+ return point(((p.x()-1)/(long)cell_size - half_block)/(long)cell_stride,
+ ((p.y()-1)/(long)cell_size - half_block)/(long)cell_stride);
+ }
+ else
+ {
+ return point(((p.x()-1-(long)cell_size/2)/(long)cell_size - half_block)/(long)cell_stride,
+ ((p.y()-1-(long)cell_size/2)/(long)cell_size - half_block)/(long)cell_stride);
+ }
+ }
+
+ const rectangle image_to_feat_space (
+ const rectangle& rect
+ ) const
+ {
+ return rectangle(image_to_feat_space(rect.tl_corner()), image_to_feat_space(rect.br_corner()));
+ }
+
+ const point feat_to_image_space (
+ const point& p
+ ) const
+ {
+ const long half_block = block_size/2;
+ if ((block_size%2) == 0)
+ {
+ return point((p.x()*cell_stride + half_block)*cell_size + 1,
+ (p.y()*cell_stride + half_block)*cell_size + 1);
+ }
+ else
+ {
+ return point((p.x()*cell_stride + half_block)*cell_size + 1 + cell_size/2,
+ (p.y()*cell_stride + half_block)*cell_size + 1 + cell_size/2);
+ }
+ }
+
+ const rectangle feat_to_image_space (
+ const rectangle& rect
+ ) const
+ {
+ return rectangle(feat_to_image_space(rect.tl_corner()), feat_to_image_space(rect.br_corner()));
+ }
+
+
+
+ // these _PRIVATE_ functions are only here as a workaround for a bug in visual studio 2005.
+ void _PRIVATE_serialize (std::ostream& out) const
+ {
+ // serialize hist_cells
+ serialize(hist_cells.nc(),out);
+ serialize(hist_cells.nr(),out);
+ hist_cells.reset();
+ while (hist_cells.move_next())
+ serialize(hist_cells.element().values,out);
+ hist_cells.reset();
+
+
+ serialize(num_block_rows, out);
+ serialize(num_block_cols, out);
+ }
+
+ void _PRIVATE_deserialize (std::istream& in )
+ {
+ // deserialize item.hist_cells
+ long nc, nr;
+ deserialize(nc,in);
+ deserialize(nr,in);
+ hist_cells.set_size(nr,nc);
+ while (hist_cells.move_next())
+ deserialize(hist_cells.element().values,in);
+ hist_cells.reset();
+
+
+ deserialize(num_block_rows, in);
+ deserialize(num_block_cols, in);
+ }
+
+ private:
+
+ template <
+ typename image_type
+ >
+ void load_impl (
+ const image_type& img
+ )
+ {
+ // Note that we keep a border of 1 pixel all around the image so that we don't have
+ // to worry about running outside the image when computing the horizontal and vertical
+ // gradients.
+
+ // Note also that we have a border of unused cells around the hist_cells array so that we
+ // don't have to worry about edge effects when doing the interpolation in the main loop
+ // below.
+
+
+ // check if the window is just too small
+ if (img.nr() < min_size || img.nc() < min_size)
+ {
+ // If the image is smaller than our windows then there aren't any descriptors at all!
+ num_block_rows = 0;
+ num_block_cols = 0;
+ return;
+ }
+
+ // Make sure we have the right number of cell histograms and that they are
+ // all set to zero.
+ hist_cells.set_size((img.nr()-2)/cell_size+2, (img.nc()-2)/cell_size+2);
+ for (long r = 0; r < hist_cells.nr(); ++r)
+ {
+ for (long c = 0; c < hist_cells.nc(); ++c)
+ {
+ hist_cells[r][c].zero();
+ }
+ }
+
+
+ // loop over all the histogram cells and fill them out
+ for (long rh = 1; rh < hist_cells.nr()-1; ++rh)
+ {
+ for (long ch = 1; ch < hist_cells.nc()-1; ++ch)
+ {
+ // Fill out the current histogram cell.
+ // First, figure out the row and column offsets into the image for the current histogram cell.
+ const long roff = (rh-1)*cell_size + 1;
+ const long coff = (ch-1)*cell_size + 1;
+
+ for (long r = 0; r < (long)cell_size; ++r)
+ {
+ for (long c = 0; c < (long)cell_size; ++c)
+ {
+ unsigned long left;
+ unsigned long right;
+ unsigned long top;
+ unsigned long bottom;
+
+ assign_pixel(left, img(r+roff,c+coff-1));
+ assign_pixel(right, img(r+roff,c+coff+1));
+ assign_pixel(top, img(r+roff-1,c+coff));
+ assign_pixel(bottom, img(r+roff+1,c+coff));
+
+ double grad_x = (long)right-(long)left;
+ double grad_y = (long)top-(long)bottom;
+
+ // obtain the angle of the gradient. Make sure it is scaled between 0 and 1.
+ double angle = std::max(0.0, std::atan2(grad_y, grad_x)/pi + 1)/2;
+
+
+ if (gradient_type == hog_unsigned_gradient)
+ {
+ angle *= 2;
+ if (angle >= 1)
+ angle -= 1;
+ }
+
+
+ // now scale angle to between 0 and num_orientation_bins
+ angle *= num_orientation_bins;
+
+
+ const double strength = std::sqrt(grad_y*grad_y + grad_x*grad_x);
+
+
+ if (interpolation_type == hog_no_interpolation)
+ {
+ // no interpolation
+ hist_cells[rh][ch].values[round_to_int(angle)%num_orientation_bins] += strength;
+ }
+ else // if we should do some interpolation
+ {
+ unsigned long quantized_angle_lower = static_cast<unsigned long>(std::floor(angle));
+ unsigned long quantized_angle_upper = static_cast<unsigned long>(std::ceil(angle));
+
+ quantized_angle_lower %= num_orientation_bins;
+ quantized_angle_upper %= num_orientation_bins;
+
+ const double angle_split = (angle-std::floor(angle));
+ const double upper_strength = angle_split*strength;
+ const double lower_strength = (1-angle_split)*strength;
+
+ if (interpolation_type == hog_angle_interpolation)
+ {
+ // Stick into gradient histogram. Note that we linearly interpolate between neighboring
+ // histogram buckets.
+ hist_cells[rh][ch].values[quantized_angle_lower] += lower_strength;
+ hist_cells[rh][ch].values[quantized_angle_upper] += upper_strength;
+ }
+ else // here we do hog_full_interpolation
+ {
+ const double center_r = (cell_size-1)/2.0;
+ const double center_c = (cell_size-1)/2.0;
+
+ const double lin_neighbor_r = std::abs(center_r - r)/cell_size;
+ const double lin_main_r = 1-lin_neighbor_r;
+
+ const double lin_neighbor_c = std::abs(center_c - c)/cell_size;
+ const double lin_main_c = 1-lin_neighbor_c;
+
+ // Which neighboring cells we interpolate into depends on which
+ // corner of our main cell we are nearest.
+ if (r < center_r)
+ {
+ if (c < center_c)
+ {
+ hist_cells[rh][ch].values[quantized_angle_upper] += upper_strength * lin_main_r*lin_main_c;
+ hist_cells[rh][ch].values[quantized_angle_lower] += lower_strength * lin_main_r*lin_main_c;
+
+ hist_cells[rh-1][ch].values[quantized_angle_upper] += upper_strength * lin_neighbor_r*lin_main_c;
+ hist_cells[rh-1][ch].values[quantized_angle_lower] += lower_strength * lin_neighbor_r*lin_main_c;
+
+ hist_cells[rh][ch-1].values[quantized_angle_upper] += upper_strength * lin_neighbor_c*lin_main_r;
+ hist_cells[rh][ch-1].values[quantized_angle_lower] += lower_strength * lin_neighbor_c*lin_main_r;
+
+ hist_cells[rh-1][ch-1].values[quantized_angle_upper] += upper_strength * lin_neighbor_c*lin_neighbor_r;
+ hist_cells[rh-1][ch-1].values[quantized_angle_lower] += lower_strength * lin_neighbor_c*lin_neighbor_r;
+ }
+ else
+ {
+ hist_cells[rh][ch].values[quantized_angle_upper] += upper_strength * lin_main_r*lin_main_c;
+ hist_cells[rh][ch].values[quantized_angle_lower] += lower_strength * lin_main_r*lin_main_c;
+
+ hist_cells[rh-1][ch].values[quantized_angle_upper] += upper_strength * lin_neighbor_r*lin_main_c;
+ hist_cells[rh-1][ch].values[quantized_angle_lower] += lower_strength * lin_neighbor_r*lin_main_c;
+
+ hist_cells[rh][ch+1].values[quantized_angle_upper] += upper_strength * lin_neighbor_c*lin_main_r;
+ hist_cells[rh][ch+1].values[quantized_angle_lower] += lower_strength * lin_neighbor_c*lin_main_r;
+
+ hist_cells[rh-1][ch+1].values[quantized_angle_upper] += upper_strength * lin_neighbor_c*lin_neighbor_r;
+ hist_cells[rh-1][ch+1].values[quantized_angle_lower] += lower_strength * lin_neighbor_c*lin_neighbor_r;
+ }
+ }
+ else
+ {
+ if (c < center_c)
+ {
+ hist_cells[rh][ch].values[quantized_angle_upper] += upper_strength * lin_main_r*lin_main_c;
+ hist_cells[rh][ch].values[quantized_angle_lower] += lower_strength * lin_main_r*lin_main_c;
+
+ hist_cells[rh+1][ch].values[quantized_angle_upper] += upper_strength * lin_neighbor_r*lin_main_c;
+ hist_cells[rh+1][ch].values[quantized_angle_lower] += lower_strength * lin_neighbor_r*lin_main_c;
+
+ hist_cells[rh][ch-1].values[quantized_angle_upper] += upper_strength * lin_neighbor_c*lin_main_r;
+ hist_cells[rh][ch-1].values[quantized_angle_lower] += lower_strength * lin_neighbor_c*lin_main_r;
+
+ hist_cells[rh+1][ch-1].values[quantized_angle_upper] += upper_strength * lin_neighbor_c*lin_neighbor_r;
+ hist_cells[rh+1][ch-1].values[quantized_angle_lower] += lower_strength * lin_neighbor_c*lin_neighbor_r;
+ }
+ else
+ {
+ hist_cells[rh][ch].values[quantized_angle_upper] += upper_strength * lin_main_r*lin_main_c;
+ hist_cells[rh][ch].values[quantized_angle_lower] += lower_strength * lin_main_r*lin_main_c;
+
+ hist_cells[rh+1][ch].values[quantized_angle_upper] += upper_strength * lin_neighbor_r*lin_main_c;
+ hist_cells[rh+1][ch].values[quantized_angle_lower] += lower_strength * lin_neighbor_r*lin_main_c;
+
+ hist_cells[rh][ch+1].values[quantized_angle_upper] += upper_strength * lin_neighbor_c*lin_main_r;
+ hist_cells[rh][ch+1].values[quantized_angle_lower] += lower_strength * lin_neighbor_c*lin_main_r;
+
+ hist_cells[rh+1][ch+1].values[quantized_angle_upper] += upper_strength * lin_neighbor_c*lin_neighbor_r;
+ hist_cells[rh+1][ch+1].values[quantized_angle_lower] += lower_strength * lin_neighbor_c*lin_neighbor_r;
+ }
+ }
+ }
+ }
+
+
+ }
+ }
+ }
+ }
+
+
+ // Now figure out how many blocks we should have. Note again that the hist_cells has a border of
+ // unused cells (thats where that -2 comes from).
+ num_block_rows = (hist_cells.nr()-2 - (block_size-1) + cell_stride - 1)/cell_stride;
+ num_block_cols = (hist_cells.nc()-2 - (block_size-1) + cell_stride - 1)/cell_stride;
+
+ }
+
+ unsigned long round_to_int(
+ double val
+ ) const
+ {
+ return static_cast<unsigned long>(std::floor(val + 0.5));
+ }
+
+ struct histogram
+ {
+ void zero()
+ {
+ for (unsigned long i = 0; i < num_orientation_bins; ++i)
+ values[i] = 0;
+ }
+ double values[num_orientation_bins];
+ };
+
+ array2d<histogram> hist_cells;
+
+ mutable descriptor_type des;
+
+ long num_block_rows;
+ long num_block_cols;
+
+
+ };
+
+// ----------------------------------------------------------------------------------------
+
+ template <
+ unsigned long T1,
+ unsigned long T2,
+ unsigned long T3,
+ unsigned long T4,
+ int T5,
+ int T6
+ >
+ void serialize (
+ const hog_image<T1,T2,T3,T4,T5,T6>& item,
+ std::ostream& out
+ )
+ {
+ item._PRIVATE_serialize(out);
+ }
+
+ template <
+ unsigned long T1,
+ unsigned long T2,
+ unsigned long T3,
+ unsigned long T4,
+ int T5,
+ int T6
+ >
+ void deserialize (
+ hog_image<T1,T2,T3,T4,T5,T6>& item,
+ std::istream& in
+ )
+ {
+ item._PRIVATE_deserialize(in);
+ }
+
+// ----------------------------------------------------------------------------------------
+
+}
+
+#endif // DLIB_HoG_Hh_
+
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