    // Copyright (C) 2016  Davis E. King (davis@dlib.net)
    // License: Boost Software License   See LICENSE.txt for the full license.
    #undef DLIB_RaNDOM_CROPPER_ABSTRACT_H_
    #ifdef DLIB_RaNDOM_CROPPER_ABSTRACT_H_

    #include "../threads.h"
    #include <mutex>
    #include <vector>
    #include "interpolation.h"
    #include "../image_processing/full_object_detection.h"
    #include "../rand.h"

    namespace dlib
    {
        class random_cropper
        {
            /*!
                WHAT THIS OBJECT REPRESENTS
                    This object is a tool for extracting random crops of objects from a set of
                    images.  The crops are randomly jittered in scale, translation, and
                    rotation but more or less centered on objects specified by mmod_rect
                    objects.

                THREAD SAFETY
                    It is safe for multiple threads to make concurrent calls to this object's
                    operator() methods.
            !*/

        public:

            random_cropper (
            );
            /*!
                ensures
                    - #get_chip_dims() == chip_dims(300,300)
                    - #get_randomly_flip() == true
                    - #get_max_rotation_degrees() == 30
                    - #get_min_object_height() == 0.25
                    - #get_max_object_height() == 0.7
                    - #get_background_crops_fraction() == 0.5
            !*/

            void set_seed (
                time_t seed
            );
            /*!
                ensures
                    - Seeds the internal random number generator with the given seed.
            !*/

            double get_background_crops_fraction (
            ) const;
            /*!
                ensures
                    - When making random crops, get_background_crops_fraction() fraction of
                      them will be from random background rather than being centered on some
                      object in the dataset.
            !*/

            void set_background_crops_fraction (
                double value
            );
            /*!
                requires
                    - 0 <= value < 1
                ensures
                    - #get_background_crops_fraction() == value
            !*/

            const chip_dims& get_chip_dims(
            ) const;
            /*!
                ensures
                    - returns the dimensions of image chips produced by this object.
            !*/

            void set_chip_dims (
                const chip_dims& dims
            );
            /*!
                ensures
                    - #get_chip_dims() == dims
            !*/

            void set_chip_dims (
                unsigned long rows,
                unsigned long cols
            );
            /*!
                ensures
                    - #get_chip_dims() == chip_dims(rows,cols)
            !*/

            bool get_randomly_flip (
            ) const;
            /*!
                ensures
                    - if this object will randomly mirror chips left to right.
            !*/

            void set_randomly_flip (
                bool value
            );
            /*!
                ensures
                    - #get_randomly_flip() == value
            !*/

            double get_max_rotation_degrees (
            ) const;
            /*!
                ensures
                    - When extracting an image chip, this object will pick a random rotation
                      in the range [-get_max_rotation_degrees(), get_max_rotation_degrees()]
                      and rotate the chip by that amount.
            !*/

            void set_max_rotation_degrees (
                double value
            );
            /*!
                ensures
                    - #get_max_rotation_degrees() == std::abs(value)
            !*/

            double get_min_object_height (
            ) const;
            /*!
                ensures
                    - When a chip is extracted around an object, the chip will be sized so that
                      the object's height is at least get_min_object_height() percent of the
                      chip height.
            !*/

            void set_min_object_height (
                double value
            );
            /*!
                requires
                    - 0 < value < 1
                ensures
                    - #get_min_object_height() == value
            !*/

            double get_max_object_height (
            ) const;
            /*!
                ensures
                    - When a chip is extracted around an object, the chip will be sized so that
                      the object's height is at most get_min_object_height() percent of the
                      chip height.
            !*/

            void set_max_object_height (
                double value
            );
            /*!
                requires
                    - 0 < value < 1
                ensures
                    - #get_max_object_height() == value
            !*/

            template <
                typename array_type
                >
            void operator() (
                size_t num_crops,
                const array_type& images,
                const std::vector<std::vector<mmod_rect>>& rects,
                array_type& crops,
                std::vector<std::vector<mmod_rect>>& crop_rects
            );
            /*!
                requires
                    - images.size() == rects.size()
                    - for all valid i:
                        - images[i].size() != 0
                    - array_type is a type with an interface compatible with dlib::array or
                      std::vector and it must in turn contain image objects that implement the
                      interface defined in dlib/image_processing/generic_image.h
                ensures
                    - Randomly extracts num_crops chips from images.  We also copy the object
                      metadata for each extracted crop and store it into #crop_rects.  In
                      particular, calling this function is the same as invoking the version of
                      operator() below multiple times, except that this version of operator()
                      will use multiple CPU cores to do the processing and is therefore faster.
            !*/

            template <
                typename array_type,
                typename image_type
                >
            void operator() (
                const array_type& images,
                const std::vector<std::vector<mmod_rect>>& rects,
                image_type& crop,
                std::vector<mmod_rect>& crop_rects
            );
            /*!
                requires
                    - images.size() == rects.size()
                    - for all valid i:
                        - images[i].size() != 0
                    - image_type == an image object that implements the interface defined in
                      dlib/image_processing/generic_image.h
                    - array_type is a type with an interface compatible with dlib::array or
                      std::vector and it must in turn contain image objects that implement the
                      interface defined in dlib/image_processing/generic_image.h
                ensures
                    - Selects a random image and creates a random crop from it.  Specifically,
                      we pick a random index IDX < images.size() and then execute
                        (*this)(images[IDX],rects[IDX],crop,crop_rects)
            !*/

            template <
                typename image_type1,
                typename image_type2
                >
            void operator() (
                const image_type1& img,
                const std::vector<mmod_rect>& rects,
                image_type2& crop,
                std::vector<mmod_rect>& crop_rects
            );
            /*!
                requires
                    - img.size() != 0
                    - image_type1 == an image object that implements the interface defined in
                      dlib/image_processing/generic_image.h
                    - image_type2 == an image object that implements the interface defined in
                      dlib/image_processing/generic_image.h
                ensures
                    - Extracts a random crop from img and copies over the mmod_rect objects in
                      rects to #crop_rects if they are contained inside the crop.  Moreover,
                      rectangles are marked as ignore if they aren't completely contained
                      inside the crop.
                    - #crop_rects.size() <= rects.size()
            !*/
        };

    }

    #endif // DLIB_RaNDOM_CROPPER_ABSTRACT_H_