// Copyright (C) 2011 Davis E. King (davis@dlib.net) // License: Boost Software License See LICENSE.txt for the full license. #undef DLIB_POLY_ImAGE_ABSTRACT_Hh_ #ifdef DLIB_POLY_ImAGE_ABSTRACT_Hh_ #include "../algs.h" #include "../matrix.h" #include "../geometry/rectangle_abstract.h" #include <cmath> #include "../image_processing/generic_image.h" namespace dlib{template <longDownsample > classpoly_image: noncopyable{/*! REQUIREMENTS ON TEMPLATE PARAMETERS - Downsample >= 1 WHAT THIS OBJECT REPRESENTS This object is a tool for extracting local feature descriptors from an image. In particular, it fits polynomials to local pixel patches and allows you to query the coefficients of these polynomials. Additionally, the coefficients may be intensity normalized by dividing them by the constant term of the fitted polynomial and then the constant term is discarded. Finally, the user can specify a downsampling rate. If the template argument Downsample is set to 1 then feature extraction is performed at every pixel of an input image (except for a small area around the image border). However, if Downsample is set to 2 then feature extraction is only performed at every other pixel location. More generally, if Downsample is set to N then feature extraction is performed only every N pixels. THREAD SAFETY Concurrent access to an instance of this object is not safe and should be protected by a mutex lock except for the case where you are copying the configuration (via copy_configuration()) of a poly_image object to many other threads. In this case, it is safe to copy the configuration of a shared object so long as no other operations are performed on it. !*/ public: typedef matrix<double, 0, 1> descriptor_type; const staticlongdownsample = Downsample;poly_image( ); /*! ensures - #get_order() == 3 - #get_window_size() == 13 - #size() == 0 - #uses_normalization() == true - #is_rotationally_invariant() == false !*/poly_image(longorder,longwindow_size,boolnormalization = true,boolrotation_invariance = false ); /*! requires - 1 <= order <= 6 - window_size >= 3 && window_size is odd ensures - #get_order() == order - #get_window_size() == window_size - #size() == 0 - #uses_normalization() == normalization - #is_rotationally_invariant() == rotation_invariance !*/voidclear( ); /*! ensures - this object will have its initial value !*/voidsetup(longorder,longwindow_size ); /*! requires - 1 <= order <= 6 - window_size >= 3 && window_size is odd ensures - #get_order() == order - #get_window_size() == window_size !*/longget_order( ) const; /*! ensures - returns the order of the polynomial that will be fitted to each local pixel patch during feature extraction. !*/longget_window_size( ) const; /*! ensures - returns the size of the window used for local feature extraction. This is the width and height of the window in pixels. !*/booluses_normalization( ) const; /*! ensures - returns true if the polynomial coefficients are intensity normalized and false otherwise. !*/voidset_uses_normalization(boolnormalization ); /*! ensures - #uses_normalization() == normalization !*/boolis_rotationally_invariant( ); /*! ensures - returns true if the feature extractor will adjust the output so that it is rotationally invariant. This is done by rotating each patch such that the gradient vector always points in the same direction. !*/voidset_is_rotationally_invariant(boolrotation_invariance ); /*! ensures - #is_rotationally_invariant() == rotation_invariance !*/voidcopy_configuration( const poly_image& item ); /*! ensures - copies all the state information of item into *this, except for state information populated by load(). More precisely, given two poly_image objects H1 and H2, the following sequence of instructions should always result in both of them having the exact same state. H2.copy_configuration(H1); H1.load(img); H2.load(img); !*/ template < typename image_type > inlinevoidload( const image_type& img ); /*! requires - image_type == an image object that implements the interface defined in dlib/image_processing/generic_image.h - pixel_traits<typename image_traits<image_type>::pixel_type>::has_alpha == false ensures - Performs the feature extraction described in the WHAT THIS OBJECT REPRESENTS section above. This means after load() finishes you can call (*this)(row,col) to obtain the polynomial coefficients for an order get_order() polynomial which was fitted to the image patch get_block_rect(row,col). - #size() > 0 !*/voidunload( ); /*! ensures - #nr() == 0 - #nc() == 0 - clears only the state information which is populated by load(). For example, let H be a poly_image object. Then consider the two sequences of instructions: Sequence 1: H.load(img); H.unload(); H.load(img); Sequence 2: H.load(img); Both sequence 1 and sequence 2 should have the same effect on H. !*/ inlineunsignedlongsize( ) const; /*! ensures - returns nr()*nc() !*/ inlinelongnr( ) const; /*! ensures - returns the number of rows in this polynomial feature image !*/ inlinelongnc( ) const; /*! ensures - returns the number of columns in this polynomial feature image !*/longget_num_dimensions( ) const; /*! ensures - returns the number of dimensions in the feature vectors generated by this object. - In this case, this will be the number of coefficients in an order get_order() polynomial, except for the constant term of the polynomial if uses_normalization() == true. !*/ inline const descriptor_type&operator() (longrow,longcol ) const; /*! requires - 0 <= row < nr() - 0 <= col < nc() ensures - returns the descriptor for the polynomial filtering block at the given row and column. This vector will contain the polynomial coefficients for a polynomial fitted to the image patch located at get_block_rect(row,col) in the original image given to load(). - The returned descriptor vector will have get_num_dimensions() elements. !*/ const rectangleget_block_rect(longrow,longcol ) const; /*! ensures - returns a rectangle that tells you what part of the original image is associated with a particular polynomial filter block. That is, what part of the input image is associated with (*this)(row,col). - The returned rectangle will be get_window_size() pixels wide and tall. !*/ const pointimage_to_feat_space( const point& p ) const; /*! ensures - Each local feature is extracted from a certain point in the input image. This function returns the identity of the local feature corresponding to the image location p. Or in other words, let P == image_to_feat_space(p), then (*this)(P.y(),P.x()) == the local feature closest to, or centered at, the point p in the input image. Note that some image points might not have corresponding feature locations. E.g. border points or points outside the image. In these cases the returned point will be outside get_rect(*this). !*/ const rectangleimage_to_feat_space( const rectangle& rect ) const; /*! ensures - returns rectangle(image_to_feat_space(rect.tl_corner()), image_to_feat_space(rect.br_corner())); (i.e. maps a rectangle from image space to feature space) !*/ const pointfeat_to_image_space( const point& p ) const; /*! ensures - returns the location in the input image space corresponding to the center of the local feature at point p. In other words, this function computes the inverse of image_to_feat_space(). Note that it may only do so approximately, since more than one image location might correspond to the same local feature. That is, image_to_feat_space() might not be invertible so this function gives the closest possible result. !*/ const rectanglefeat_to_image_space( const rectangle& rect ) const; /*! ensures - return rectangle(feat_to_image_space(rect.tl_corner()), feat_to_image_space(rect.br_corner())); (i.e. maps a rectangle from feature space to image space) !*/}; // ---------------------------------------------------------------------------------------- template <longdownsample >voidserialize( const poly_image<downsample>& item, std::ostream& out ); /*! provides serialization support !*/ template <longdownsample >voiddeserialize( poly_image<downsample>& item, std::istream& in ); /*! provides deserialization support !*/ // ----------------------------------------------------------------------------------------}#endif // DLIB_POLY_ImAGE_ABSTRACT_Hh_