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-rw-r--r--ml/dlib/dlib/image_keypoint/fine_hog_image.h378
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diff --git a/ml/dlib/dlib/image_keypoint/fine_hog_image.h b/ml/dlib/dlib/image_keypoint/fine_hog_image.h
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+++ b/ml/dlib/dlib/image_keypoint/fine_hog_image.h
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+// Copyright (C) 2012 Davis E. King (davis@dlib.net)
+// License: Boost Software License See LICENSE.txt for the full license.
+#ifndef DLIB_FINE_HOG_IMaGE_Hh_
+#define DLIB_FINE_HOG_IMaGE_Hh_
+
+#include "fine_hog_image_abstract.h"
+#include "../array2d.h"
+#include "../matrix.h"
+#include "hog.h"
+
+
+namespace dlib
+{
+ template <
+ unsigned long cell_size_,
+ unsigned long block_size_,
+ unsigned long pixel_stride_,
+ unsigned char num_orientation_bins_,
+ int gradient_type_
+ >
+ class fine_hog_image : noncopyable
+ {
+ COMPILE_TIME_ASSERT(cell_size_ > 1);
+ COMPILE_TIME_ASSERT(block_size_ > 0);
+ COMPILE_TIME_ASSERT(pixel_stride_ > 0);
+ COMPILE_TIME_ASSERT(num_orientation_bins_ > 0);
+
+ COMPILE_TIME_ASSERT( gradient_type_ == hog_signed_gradient ||
+ gradient_type_ == hog_unsigned_gradient);
+
+
+ public:
+
+ const static unsigned long cell_size = cell_size_;
+ const static unsigned long block_size = block_size_;
+ const static unsigned long pixel_stride = pixel_stride_;
+ const static unsigned long num_orientation_bins = num_orientation_bins_;
+ const static int gradient_type = gradient_type_;
+
+ const static long min_size = cell_size*block_size+2;
+
+ typedef matrix<double, block_size*block_size*num_orientation_bins, 1> descriptor_type;
+
+ fine_hog_image (
+ ) :
+ num_block_rows(0),
+ num_block_cols(0)
+ {}
+
+ void clear (
+ )
+ {
+ num_block_rows = 0;
+ num_block_cols = 0;
+ hist_counts.clear();
+ }
+
+ void copy_configuration (
+ const fine_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 fine_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 *= pixel_stride;
+ col *= pixel_stride;
+
+ des = 0;
+ unsigned long off = 0;
+ for (unsigned long r = 0; r < block_size; ++r)
+ {
+ for (unsigned long c = 0; c < block_size; ++c)
+ {
+ for (unsigned long rr = 0; rr < cell_size; ++rr)
+ {
+ for (unsigned long cc = 0; cc < cell_size; ++cc)
+ {
+ const histogram_count& hist = hist_counts[row + r*cell_size + rr][col + c*cell_size + cc];
+ des(off + hist.quantized_angle_lower) += hist.lower_strength;
+ des(off + hist.quantized_angle_upper) += hist.upper_strength;
+ }
+ }
+
+ off += num_orientation_bins;
+ }
+ }
+
+ des /= length(des) + 1e-8;
+
+ return des;
+ }
+
+ const rectangle get_block_rect (
+ long row,
+ long col
+ ) const
+ {
+ row *= pixel_stride;
+ col *= pixel_stride;
+
+ // 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 border_size = 1 + cell_size*block_size/2;
+ return (p-point(border_size,border_size))/(long)pixel_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 border_size = 1 + cell_size*block_size/2;
+ return p*(long)pixel_stride + point(border_size,border_size);
+ }
+
+ 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_counts
+ serialize(hist_counts.nc(),out);
+ serialize(hist_counts.nr(),out);
+ hist_counts.reset();
+ while (hist_counts.move_next())
+ hist_counts.element().serialize(out);
+ hist_counts.reset();
+
+
+ serialize(num_block_rows, out);
+ serialize(num_block_cols, out);
+ }
+
+ void _PRIVATE_deserialize (std::istream& in )
+ {
+ // deserialize item.hist_counts
+ long nc, nr;
+ deserialize(nc,in);
+ deserialize(nr,in);
+ hist_counts.set_size(nr,nc);
+ while (hist_counts.move_next())
+ hist_counts.element().deserialize(in);
+ hist_counts.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.
+
+
+
+ // 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;
+ hist_counts.clear();
+ return;
+ }
+
+ hist_counts.set_size(img.nr()-2, img.nc()-2);
+
+
+
+
+ for (long r = 0; r < hist_counts.nr(); ++r)
+ {
+ for (long c = 0; c < hist_counts.nc(); ++c)
+ {
+ unsigned long left;
+ unsigned long right;
+ unsigned long top;
+ unsigned long bottom;
+
+ assign_pixel(left, img(r+1,c));
+ assign_pixel(right, img(r+1,c+2));
+ assign_pixel(top, img(r ,c+1));
+ assign_pixel(bottom, img(r+2,c+1));
+
+ 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);
+
+
+ unsigned char quantized_angle_lower = static_cast<unsigned char>(std::floor(angle));
+ unsigned char quantized_angle_upper = static_cast<unsigned char>(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;
+
+ // Stick into gradient counts. Note that we linearly interpolate between neighboring
+ // histogram buckets.
+ hist_counts[r][c].quantized_angle_lower = quantized_angle_lower;
+ hist_counts[r][c].quantized_angle_upper = quantized_angle_upper;
+ hist_counts[r][c].lower_strength = lower_strength;
+ hist_counts[r][c].upper_strength = upper_strength;
+
+ }
+ }
+
+
+ // Now figure out how many feature extraction blocks we should have.
+ num_block_rows = (hist_counts.nr() - block_size*cell_size + 1)/(long)pixel_stride;
+ num_block_cols = (hist_counts.nc() - block_size*cell_size + 1)/(long)pixel_stride;
+
+ }
+
+ struct histogram_count
+ {
+ unsigned char quantized_angle_lower;
+ unsigned char quantized_angle_upper;
+ float lower_strength;
+ float upper_strength;
+
+ void serialize(std::ostream& out) const
+ {
+ dlib::serialize(quantized_angle_lower, out);
+ dlib::serialize(quantized_angle_upper, out);
+ dlib::serialize(lower_strength, out);
+ dlib::serialize(upper_strength, out);
+ }
+ void deserialize(std::istream& in)
+ {
+ dlib::deserialize(quantized_angle_lower, in);
+ dlib::deserialize(quantized_angle_upper, in);
+ dlib::deserialize(lower_strength, in);
+ dlib::deserialize(upper_strength, in);
+ }
+ };
+
+ array2d<histogram_count> hist_counts;
+
+ mutable descriptor_type des;
+
+ long num_block_rows;
+ long num_block_cols;
+
+
+ };
+
+// ----------------------------------------------------------------------------------------
+
+ template <
+ unsigned long T1,
+ unsigned long T2,
+ unsigned long T3,
+ unsigned char T4,
+ int T5
+ >
+ void serialize (
+ const fine_hog_image<T1,T2,T3,T4,T5>& item,
+ std::ostream& out
+ )
+ {
+ item._PRIVATE_serialize(out);
+ }
+
+ template <
+ unsigned long T1,
+ unsigned long T2,
+ unsigned long T3,
+ unsigned char T4,
+ int T5
+ >
+ void deserialize (
+ fine_hog_image<T1,T2,T3,T4,T5>& item,
+ std::istream& in
+ )
+ {
+ item._PRIVATE_deserialize(in);
+ }
+
+// ----------------------------------------------------------------------------------------
+
+}
+
+#endif // DLIB_FINE_HOG_IMaGE_Hh_
+
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