text: // License: Apache 2.0. See LICENSE file in root directory.
  // Copyright(c) 2017 Intel Corporation. All Rights Reserved.
  
  #ifndef LIBREALSENSE_RS2_PROCESSING_HPP
  #define LIBREALSENSE_RS2_PROCESSING_HPP
  
  #include "rs_types.hpp"
  #include "rs_frame.hpp"
  #include "rs_options.hpp"
  
  namespace rs2
  {
      /**
      * The source used to generate frames, which is usually done by the low level driver for each sensor. frame_source is one of the parameters
      * of processing_block's callback function, which can be used to re-generate the frame and via frame_ready invoke another callback function
      * to notify application frame is ready. Please refer to "video_processing_thread" code snippet in rs-measure.cpp for a detailed usage example.
      */
      class frame_source
      {
      public:
          /**
          * Allocate a new video frame with given params
          *
          * \param[in] profile     Stream profile going to allocate.
          * \param[in] original    Original frame, if new_bpp, new_width, new_height or new_stride is zero, newly created frame will base on original frame's metadata to allocate new frame. If frame_type is RS2_EXTENSION_DEPTH_FRAME, the original of the returned frame will be set to it.
          * \param[in] new_bpp     Frame bit per pixel to create.
          * \param[in] new_width   Frame width to create.
          * \param[in] new_height  Frame height to create.
          * \param[in] new_stride  Frame stride to crate.
          * \param[in] frame_type  Which frame type are going to create.
          * \return   The allocated frame
          */
          frame allocate_video_frame(const stream_profile& profile,
              const frame& original,
              int new_bpp = 0,
              int new_width = 0,
              int new_height = 0,
              int new_stride = 0,
              rs2_extension frame_type = RS2_EXTENSION_VIDEO_FRAME) const
          {
              rs2_error* e = nullptr;
              auto result = rs2_allocate_synthetic_video_frame(_source, profile.get(),
                  original.get(), new_bpp, new_width, new_height, new_stride, frame_type, &e);
              error::handle(e);
              return result;
          }
  
          frame allocate_points(const stream_profile& profile,
              const frame& original) const
          {
              rs2_error* e = nullptr;
              auto result = rs2_allocate_points(_source, profile.get(), original.get(), &e);
              error::handle(e);
              return result;
          }
  
          /**
          * Allocate composite frame with given params
          *
          * \param[in] frames      Frame vecotor used to create composite frame, the size of composite frame will be the same as vector size.
          * \return    The allocated composite frame
          */
          frame allocate_composite_frame(std::vector<frame> frames) const
          {
              rs2_error* e = nullptr;
  
              std::vector<rs2_frame*> refs(frames.size(), (rs2_frame*)nullptr);
              for (size_t i = 0; i < frames.size(); i++)
                  std::swap(refs[i], frames[i].frame_ref);
  
              auto result = rs2_allocate_composite_frame(_source, refs.data(), (int)refs.size(), &e);
              error::handle(e);
              return result;
          }
          /**
          * Invoke the callback funtion informing the frame is ready.
          *
          * \param[in] frames      frame to send to callback function.
          */
          void frame_ready(frame result) const
          {
              rs2_error* e = nullptr;
              rs2_synthetic_frame_ready(_source, result.get(), &e);
              error::handle(e);
              result.frame_ref = nullptr;
          }
  
          rs2_source* _source;
      private:
          template<class T>
          friend class frame_processor_callback;
  
          frame_source(rs2_source* source) : _source(source) {}
          frame_source(const frame_source&) = delete;
  
      };
  
      template<class T>
      class frame_processor_callback : public rs2_frame_processor_callback
      {
          T on_frame_function;
      public:
          explicit frame_processor_callback(T on_frame) : on_frame_function(on_frame) {}
  
          void on_frame(rs2_frame* f, rs2_source * source) override
          {
              frame_source src(source);
              frame frm(f);
              on_frame_function(std::move(frm), src);
          }
  
          void release() override { delete this; }
      };
  
      class frame_queue
      {
      public:
          /**
          * create frame queue. frame queues are the simplest x-platform synchronization primitive provided by librealsense
          * to help developers who are not using async APIs
          * param[in] capacity size of the frame queue
          */
          explicit frame_queue(unsigned int capacity) : _capacity(capacity)
          {
              rs2_error* e = nullptr;
              _queue = std::shared_ptr<rs2_frame_queue>(
                  rs2_create_frame_queue(capacity, &e),
                  rs2_delete_frame_queue);
              error::handle(e);
          }
  
          frame_queue() : frame_queue(1) {}
  
          /**
          * enqueue new frame into the queue
          * \param[in] f - frame handle to enqueue (this operation passed ownership to the queue)
          */
          void enqueue(frame f) const
          {
              rs2_enqueue_frame(f.frame_ref, _queue.get()); // noexcept
              f.frame_ref = nullptr; // frame has been essentially moved from
          }
  
          /**
          * wait until new frame becomes available in the queue and dequeue it
          * \return frame handle to be released using rs2_release_frame
          */
          frame wait_for_frame(unsigned int timeout_ms = 5000) const
          {
              rs2_error* e = nullptr;
              auto frame_ref = rs2_wait_for_frame(_queue.get(), timeout_ms, &e);
              error::handle(e);
              return{ frame_ref };
          }
  
          /**
          * poll if a new frame is available and dequeue if it is
          * \param[out] f - frame handle
          * \return true if new frame was stored to f
          */
          template<typename T>
          typename std::enable_if<std::is_base_of<rs2::frame, T>::value, bool>::type poll_for_frame(T* output) const
          {
              rs2_error* e = nullptr;
              rs2_frame* frame_ref = nullptr;
              auto res = rs2_poll_for_frame(_queue.get(), &frame_ref, &e);
              error::handle(e);
              frame f{ frame_ref };
              if (res) *output = f;
              return res > 0;
          }
  
          template<typename T>
          typename std::enable_if<std::is_base_of<rs2::frame, T>::value, bool>::type try_wait_for_frame(T* output, unsigned int timeout_ms = 5000) const
          {
              rs2_error* e = nullptr;
              rs2_frame* frame_ref = nullptr;
              auto res = rs2_try_wait_for_frame(_queue.get(), timeout_ms, &frame_ref, &e);
              error::handle(e);
              frame f{ frame_ref };
              if (res) *output = f;
              return res > 0;
          }
          /**
          * Does the same thing as enqueue function.
          */
          void operator()(frame f) const
          {
              enqueue(std::move(f));
          }
          /**
          * Return the capacity of the queue
          * \return capacity size
          */
          size_t capacity() const { return _capacity; }
  
      private:
          std::shared_ptr<rs2_frame_queue> _queue;
          size_t _capacity;
      };
  
      /**
      * Define the processing block flow, inherit this class to generate your own processing_block. Please refer to the viewer class in examples.hpp for a detailed usage example.
      */
      class processing_block : public options
      {
      public:
          using options::supports;
  
          /**
          * Start the processing block with callback function on_frame to inform the application the frame is processed.
          *
          * \param[in] on_frame      callback function for notifying the frame to be processed is ready.
          */
          template<class S>
          void start(S on_frame)
          {
              rs2_error* e = nullptr;
              rs2_start_processing(get(), new frame_callback<S>(on_frame), &e);
              error::handle(e);
          }
          /**
          * Does the same thing as "start" function
          *
          * \param[in] on_frame      address of callback function for noticing the frame to be processed is ready.
          * \return address of callback function.
          */
          template<class S>
          S& operator>>(S& on_frame)
          {
              start(on_frame);
              return on_frame;
          }
          /**
          * Ask processing block to process the frame
          *
          * \param[in] on_frame      frame to be processed.
          */
          void invoke(frame f) const
          {
              rs2_frame* ptr = nullptr;
              std::swap(f.frame_ref, ptr);
  
              rs2_error* e = nullptr;
              rs2_process_frame(get(), ptr, &e);
              error::handle(e);
          }
          /**
          * constructor with already created low level processing block assigned.
          *
          * \param[in] block - low level rs2_processing_block created before.
          */
          processing_block(std::shared_ptr<rs2_processing_block> block)
              : options((rs2_options*)block.get()), _block(block)
          {
          }
  
          /**
          * constructor with callback function on_frame in rs2_frame_processor_callback structure assigned.
          *
          * \param[in] processing_function - function pointer of on_frame function in rs2_frame_processor_callback structure, which will be called back by invoke function .
          */
          template<class S>
          processing_block(S processing_function)
          {
              rs2_error* e = nullptr;
              _block = std::shared_ptr<rs2_processing_block>(
                  rs2_create_processing_block(new frame_processor_callback<S>(processing_function), &e),
                  rs2_delete_processing_block);
              options::operator=(_block);
              error::handle(e);
          }
  
          operator rs2_options*() const { return (rs2_options*)get(); }
          rs2_processing_block* get() const { return _block.get(); }
  
          /**
          * check if specific  camera info is supported
          * \param[in] info    the parameter to check for support
          * \return            true if the parameter both exists and well-defined for the specific sensor
          */
          bool supports(rs2_camera_info info) const
          {
              rs2_error* e = nullptr;
              auto is_supported = rs2_supports_processing_block_info(_block.get(), info, &e);
              error::handle(e);
              return is_supported > 0;
          }
  
          /**
          * retrieve camera specific information, like versions of various internal components
          * \param[in] info     camera info type to retrieve
          * \return             the requested camera info string, in a format specific to the sensor model
          */
          const char* get_info(rs2_camera_info info) const
          {
              rs2_error* e = nullptr;
              auto result = rs2_get_processing_block_info(_block.get(), info, &e);
              error::handle(e);
              return result;
          }
      protected:
          void register_simple_option(rs2_option option_id, option_range range) {
              rs2_error * e = nullptr;
              rs2_processing_block_register_simple_option(_block.get(), option_id,
                      range.min, range.max, range.step, range.def, &e);
              error::handle(e);
          }
          std::shared_ptr<rs2_processing_block> _block;
      };
  
      /**
      * Define the filter workflow, inherit this class to generate your own filter. Refer to the viewer class in examples.hpp for a more detailed example.
      */
      class filter : public processing_block, public filter_interface
      {
      public:
          /**
          * Ask processing block to process the frame and poll the processed frame from internal queue
          *
          * \param[in] on_frame      frame to be processed.
          * return processed frame
          */
          rs2::frame process(rs2::frame frame) const override
          {
              invoke(frame);
              rs2::frame f;
              if (!_queue.poll_for_frame(&f))
                  throw std::runtime_error("Error occured during execution of the processing block! See the log for more info");
              return f;
          }
  
          /**
          * constructor with already created low level processing block assigned.
          *
          * \param[in] block - low level rs2_processing_block created before.
          */
          filter(std::shared_ptr<rs2_processing_block> block, int queue_size = 1)
              : processing_block(block),
              _queue(queue_size)
          {
              start(_queue);
          }
  
          /**
          * constructor with callback function on_frame in rs2_frame_processor_callback structure assigned.
          *
          * \param[in] processing_function - function pointer of on_frame function in rs2_frame_processor_callback structure, which will be called back by invoke function .
          */
          template<class S>
          filter(S processing_function, int queue_size = 1) :
              processing_block(processing_function),
              _queue(queue_size)
          {
              start(_queue);
          }
  
  
          frame_queue get_queue() { return _queue; }
          rs2_processing_block* get() const { return _block.get(); }
  
          template<class T>
          bool is() const
          {
              T extension(*this);
              return extension;
          }
  
          template<class T>
          T as() const
          {
              T extension(*this);
              return extension;
          }
  
          operator bool() const { return _block.get() != nullptr; }
      protected:
          frame_queue _queue;
      };
  
      /**
      * Generates 3D point clouds based on a depth frame. Can also map textures from a color frame.
      */
      class pointcloud : public filter
      {
      public:
          /**
          * create pointcloud instance
          */
          pointcloud() : filter(init(), 1) {}
  
          pointcloud(rs2_stream stream, int index = 0) : filter(init(), 1)
          {
              set_option(RS2_OPTION_STREAM_FILTER, float(stream));
              set_option(RS2_OPTION_STREAM_INDEX_FILTER, float(index));
          }
          /**
          * Generate the pointcloud and texture mappings of depth map.
          *
          * \param[in] depth - the depth frame to generate point cloud and texture.
          * \return points instance.
          */
          points calculate(frame depth)
          {
              auto res = process(depth);
              if (res.as<points>())
                  return res;
  
              if (auto set = res.as <frameset>())
              {
                  for (auto f : set)
                  {
                      if(f.as<points>())
                          return f;
                  }
              }
              throw std::runtime_error("Error occured during execution of the processing block! See the log for more info");
          }
          /**
          * Map the point cloud to the given color frame.
          *
          * \param[in] mapped - the frame to be mapped to as texture.
          */
          void map_to(frame mapped)
          {
              set_option(RS2_OPTION_STREAM_FILTER, float(mapped.get_profile().stream_type()));
              set_option(RS2_OPTION_STREAM_FORMAT_FILTER, float(mapped.get_profile().format()));
              set_option(RS2_OPTION_STREAM_INDEX_FILTER, float(mapped.get_profile().stream_index()));
              process(mapped);
          }
  
      protected:
          pointcloud(std::shared_ptr<rs2_processing_block> block) : filter(block, 1) {}
  
      private:
          friend class context;
  
          std::shared_ptr<rs2_processing_block> init()
          {
              rs2_error* e = nullptr;
  
              auto block = std::shared_ptr<rs2_processing_block>(
                  rs2_create_pointcloud(&e),
                  rs2_delete_processing_block);
  
              error::handle(e);
  
              // Redirect options API to the processing block
              //options::operator=(pb);
              return block;
          }
      };
  
      class yuy_decoder : public filter
      {
      public:
          /**
          * Creates YUY decoder processing block. This block accepts raw YUY frames and outputs frames of other formats.
          * YUY is a common video format used by a variety of web-cams. It benefits from packing pixels into 2 bytes per pixel
          * without signficant quality drop. YUY representation can be converted back to more usable RGB form,
          * but this requires somewhat costly conversion.
          * The SDK will automatically try to use SSE2 and AVX instructions and CUDA where available to get
          * best performance. Other implementations (using GLSL, OpenCL, Neon and NCS) should follow.
          */
          yuy_decoder() : filter(init(), 1) { }
  
      protected:
          yuy_decoder(std::shared_ptr<rs2_processing_block> block) : filter(block, 1) {}
  
      private:
          std::shared_ptr<rs2_processing_block> init()
          {
              rs2_error* e = nullptr;
              auto block = std::shared_ptr<rs2_processing_block>(
                  rs2_create_yuy_decoder(&e),
                  rs2_delete_processing_block);
              error::handle(e);
  
              return block;
          }
      };
    
    class threshold_filter : public filter
      {
      public:
          /**
          * Creates depth thresholding filter
          * By controlling min and max options on the block, one could filter out depth values
          * that are either too large or too small, as a software post-processing step
          */
          threshold_filter(float min_dist = 0.15f, float max_dist = 4.f) 
              : filter(init(), 1) 
          { 
              set_option(RS2_OPTION_MIN_DISTANCE, min_dist);
              set_option(RS2_OPTION_MAX_DISTANCE, max_dist);
          }
  
          threshold_filter(filter f) : filter(f)
          {
              rs2_error* e = nullptr;
              if (!rs2_is_processing_block_extendable_to(f.get(), RS2_EXTENSION_THRESHOLD_FILTER, &e) && !e)
              {
                  _block.reset();
              }
              error::handle(e);
          }
  
      protected:
          threshold_filter(std::shared_ptr<rs2_processing_block> block) : filter(block, 1) {}
          
      private:
          std::shared_ptr<rs2_processing_block> init()
          {
              rs2_error* e = nullptr;
              auto block = std::shared_ptr<rs2_processing_block>(
                  rs2_create_threshold(&e),
                  rs2_delete_processing_block);
              error::handle(e);
  
              return block;
          }
      };
  
      class units_transform : public filter
      {
      public:
          /**
          * Creates depth units to meters processing block.
          */
          units_transform() : filter(init(), 1) {}
  
      protected:
          units_transform(std::shared_ptr<rs2_processing_block> block) : filter(block, 1) {}
          
      private:
          std::shared_ptr<rs2_processing_block> init()
          {
              rs2_error* e = nullptr;
              auto block = std::shared_ptr<rs2_processing_block>(
                  rs2_create_units_transform(&e),
                  rs2_delete_processing_block);
              error::handle(e);
  
              return block;
          }
      };
  
      class asynchronous_syncer : public processing_block
      {
      public:
          /**
          * Real asynchronous syncer within syncer class
          */
          asynchronous_syncer() : processing_block(init()) {}
  
      private:
          std::shared_ptr<rs2_processing_block> init()
          {
              rs2_error* e = nullptr;
              auto block = std::shared_ptr<rs2_processing_block>(
                  rs2_create_sync_processing_block(&e),
                  rs2_delete_processing_block);
  
              error::handle(e);
              return block;
          }
      };
  
      class syncer
      {
      public:
          /**
          * Sync instance to align frames from different streams
          */
          syncer(int queue_size = 1)
              :_results(queue_size)
          {
              _sync.start(_results);
          }
  
          /**
          * Wait until coherent set of frames becomes available
          * \param[in] timeout_ms   Max time in milliseconds to wait until an exception will be thrown
          * \return Set of coherent frames
          */
          frameset wait_for_frames(unsigned int timeout_ms = 5000) const
          {
              return frameset(_results.wait_for_frame(timeout_ms));
          }
  
          /**
          * Check if a coherent set of frames is available
          * \param[out] fs      New coherent frame-set
          * \return true if new frame-set was stored to result
          */
          bool poll_for_frames(frameset* fs) const
          {
              frame result;
              if (_results.poll_for_frame(&result))
              {
                  *fs = frameset(result);
                  return true;
              }
              return false;
          }
  
          /**
          * Wait until coherent set of frames becomes available
          * \param[in] timeout_ms     Max time in milliseconds to wait until an available frame
          * \param[out] fs            New coherent frame-set
          * \return true if new frame-set was stored to result
          */
          bool try_wait_for_frames(frameset* fs, unsigned int timeout_ms = 5000) const
          {
              frame result;
              if (_results.try_wait_for_frame(&result, timeout_ms))
              {
                  *fs = frameset(result);
                  return true;
              }
              return false;
          }
  
          void operator()(frame f) const
          {
              _sync.invoke(std::move(f));
          }
      private:
          asynchronous_syncer _sync;
          frame_queue _results;
      };
  
      /**
      Auxiliary processing block that performs image alignment using depth data and camera calibration
      */
      class align : public filter
      {
      public:
          /**
          Create align filter
          Alignment is performed between a depth image and another image.
          To perform alignment of a depth image to the other, set the align_to parameter with the other stream type.
          To perform alignment of a non depth image to a depth image, set the align_to parameter to RS2_STREAM_DEPTH.
          Camera calibration and frame's stream type are determined on the fly, according to the first valid frameset passed to process().
  
          * \param[in] align_to      The stream type to which alignment should be made.
          */
          align(rs2_stream align_to) : filter(init(align_to), 1) {}
  
          /**
          * Run the alignment process on the given frames to get an aligned set of frames
          *
          * \param[in] frames      A set of frames, where at least one of which is a depth frame
          * \return Input frames aligned to one another
          */
          frameset process(frameset frames)
          {
              return filter::process(frames);
          }
  
      protected:
          align(std::shared_ptr<rs2_processing_block> block) : filter(block, 1) {}
  
      private:
          friend class context;
          std::shared_ptr<rs2_processing_block> init(rs2_stream align_to)
          {
              rs2_error* e = nullptr;
              auto block = std::shared_ptr<rs2_processing_block>(
                  rs2_create_align(align_to, &e),
                  rs2_delete_processing_block);
              error::handle(e);
  
              return block;
          }
      };
  
      class colorizer : public filter
      {
      public:
          /**
          * Create colorizer filter
          * Colorizer generate color image based on input depth frame
          */
          colorizer() : filter(init(), 1) { }
          /**
          * Create colorizer processing block
          * Colorizer generate color image base on input depth frame
          * \param[in] color_scheme - select one of the available color schemes:
          *                           0 - Jet
          *                           1 - Classic
          *                           2 - WhiteToBlack
          *                           3 - BlackToWhite
          *                           4 - Bio
          *                           5 - Cold
          *                           6 - Warm
          *                           7 - Quantized
          *                           8 - Pattern
          */
          colorizer(float color_scheme) : filter(init(), 1)
          {
              set_option(RS2_OPTION_COLOR_SCHEME, float(color_scheme));
          }
          /**
          * Start to generate color image base on depth frame
          * \param[in] depth - depth frame to be processed to generate the color image
          * \return video_frame - generated color image
          */
          video_frame colorize(frame depth) const
          {
              return process(depth);
          }
  
      protected:
          colorizer(std::shared_ptr<rs2_processing_block> block) : filter(block, 1) {}
  
      private:
          std::shared_ptr<rs2_processing_block> init()
          {
              rs2_error* e = nullptr;
              auto block = std::shared_ptr<rs2_processing_block>(
                  rs2_create_colorizer(&e),
                  rs2_delete_processing_block);
              error::handle(e);
  
              // Redirect options API to the processing block
              //options::operator=(pb);
  
              return block;
          }
      };
  
      class decimation_filter : public filter
      {
      public:
          /**
          * Create decimation filter
          * Decimation filter performs downsampling by using the median with specific kernel size
          */
          decimation_filter() : filter(init(), 1) {}
          /**
          * Create decimation filter
          * Decimation filter performs downsampling by using the median with specific kernel size
          * \param[in] magnitude - number of filter iterations.
          */
          decimation_filter(float magnitude) : filter(init(), 1)
          {
              set_option(RS2_OPTION_FILTER_MAGNITUDE, magnitude);
          }
  
          decimation_filter(filter f) : filter(f)
          {
               rs2_error* e = nullptr;
               if (!rs2_is_processing_block_extendable_to(f.get(), RS2_EXTENSION_DECIMATION_FILTER, &e) && !e)
               {
                   _block.reset();
               }
               error::handle(e);
          }
         
      private:
          friend class context;
  
          std::shared_ptr<rs2_processing_block> init()
          {
              rs2_error* e = nullptr;
              auto block = std::shared_ptr<rs2_processing_block>(
                  rs2_create_decimation_filter_block(&e),
                  rs2_delete_processing_block);
              error::handle(e);
  
              // Redirect options API to the processing block
              //options::operator=(this);
  
              return block;
          }
      };
  
      class temporal_filter : public filter
      {
      public:
          /**
          * Create temporal filter with default settings
          * Temporal filter smooths the image by calculating multiple frames with alpha and delta settings
          * alpha defines the weight of current frame, and delta defines the threshold for edge classification and preserving.
          * For more information, check the temporal-filter.cpp
          */
          temporal_filter() : filter(init(), 1) {}
          /**
          * Create temporal filter with user settings
          * Temporal filter smooths the image by calculating multiple frames with alpha and delta settings
          * \param[in] smooth_alpha - defines the weight of current frame.
          * \param[in] smooth_delta - delta defines the threshold for edge classification and preserving.
          * \param[in] persistence_control - A set of predefined rules (masks) that govern when missing pixels will be replaced with the last valid value so that the data will remain persistent over time:
          * 0 - Disabled - Persistency filter is not activated and no hole filling occurs.
          * 1 - Valid in 8/8 - Persistency activated if the pixel was valid in 8 out of the last 8 frames
          * 2 - Valid in 2/last 3 - Activated if the pixel was valid in two out of the last 3 frames
          * 3 - Valid in 2/last 4 - Activated if the pixel was valid in two out of the last 4 frames
          * 4 - Valid in 2/8 - Activated if the pixel was valid in two out of the last 8 frames
          * 5 - Valid in 1/last 2 - Activated if the pixel was valid in one of the last two frames
          * 6 - Valid in 1/last 5 - Activated if the pixel was valid in one out of the last 5 frames
          * 7 - Valid in 1/last 8 - Activated if the pixel was valid in one out of the last 8 frames
          * 8 - Persist Indefinitely - Persistency will be imposed regardless of the stored history(most aggressive filtering)
          * For more information, check temporal-filter.cpp
          */
          temporal_filter(float smooth_alpha, float smooth_delta, int persistence_control) : filter(init(), 1)
          {
              set_option(RS2_OPTION_HOLES_FILL, float(persistence_control));
              set_option(RS2_OPTION_FILTER_SMOOTH_ALPHA, float(smooth_alpha));
              set_option(RS2_OPTION_FILTER_SMOOTH_DELTA, float(smooth_delta));
          }
  
          temporal_filter(filter f) :filter(f)
          {
              rs2_error* e = nullptr;
              if (!rs2_is_processing_block_extendable_to(f.get(), RS2_EXTENSION_TEMPORAL_FILTER, &e) && !e)
              {
                  _block.reset();
              }
              error::handle(e);
          }
      private:
          friend class context;
  
          std::shared_ptr<rs2_processing_block> init()
          {
              rs2_error* e = nullptr;
              auto block = std::shared_ptr<rs2_processing_block>(
                  rs2_create_temporal_filter_block(&e),
                  rs2_delete_processing_block);
              error::handle(e);
  
              // Redirect options API to the processing block
              //options::operator=(pb);
  
              return block;
          }
      };
  
      class spatial_filter : public filter
      {
      public:
          /**
          * Create spatial filter
          * Spatial filter smooths the image by calculating frame with alpha and delta settings
          * alpha defines the weight of the current pixel for smoothing, and is bounded within [25..100]%,
          * delta defines the depth gradient below which the smoothing will occur as number of depth levels
          * For more information, check the spatial-filter.cpp
          */
          spatial_filter() : filter(init(), 1) { }
  
          /**
          * Create spatial filter
          * Spatial filter smooths the image by calculating frame with alpha and delta settings
          * \param[in] smooth_alpha - defines the weight of the current pixel for smoothing is bounded within [25..100]%
          * \param[in] smooth_delta - defines the depth gradient below which the smoothing will occur as number of depth levels
          * \param[in] magnitude - number of filter iterations.
          * \param[in] hole_fill - an in-place heuristic symmetric hole-filling mode applied horizontally during the filter passes.
          *                           Intended to rectify minor artefacts with minimal performance impact
          */
          spatial_filter(float smooth_alpha, float smooth_delta, float magnitude, float hole_fill) : filter(init(), 1)
          {
              set_option(RS2_OPTION_FILTER_SMOOTH_ALPHA, float(smooth_alpha));
              set_option(RS2_OPTION_FILTER_SMOOTH_DELTA, float(smooth_delta));
              set_option(RS2_OPTION_FILTER_MAGNITUDE, magnitude);
              set_option(RS2_OPTION_HOLES_FILL, hole_fill);
          }
  
          spatial_filter(filter f) :filter(f)
          {
              rs2_error* e = nullptr;
              if (!rs2_is_processing_block_extendable_to(f.get(), RS2_EXTENSION_SPATIAL_FILTER, &e) && !e)
              {
                  _block.reset();
              }
              error::handle(e);
          }
      private:
          friend class context;
  
          std::shared_ptr<rs2_processing_block> init()
          {
              rs2_error* e = nullptr;
              auto block = std::shared_ptr<rs2_processing_block>(
                  rs2_create_spatial_filter_block(&e),
                  rs2_delete_processing_block);
              error::handle(e);
  
              // Redirect options API to the processing block
              //options::operator=(pb);
  
              return block;
          }
      };
  
      class disparity_transform : public filter
      {
      public:
          /**
          * Create disparity transform filter
          * Converts from depth representation to disparity representation and vice-versa in depth frames
          */
          disparity_transform(bool transform_to_disparity = true) : filter(init(transform_to_disparity), 1) { }
  
          disparity_transform(filter f) :filter(f)
          {
              rs2_error* e = nullptr;
              if (!rs2_is_processing_block_extendable_to(f.get(), RS2_EXTENSION_DISPARITY_FILTER, &e) && !e)
              {
                  _block.reset();
              }
              error::handle(e);
          }
      private:
          friend class context;
          std::shared_ptr<rs2_processing_block> init(bool transform_to_disparity)
          {
              rs2_error* e = nullptr;
              auto block = std::shared_ptr<rs2_processing_block>(
                  rs2_create_disparity_transform_block(uint8_t(transform_to_disparity), &e),
                  rs2_delete_processing_block);
              error::handle(e);
  
              // Redirect options API to the processing block
              //options::operator=(pb);
  
              return block;
          }
      };
      
      class zero_order_invalidation : public filter
      {
      public:
          /**
          * Create zero order fix filter
          * The filter fixes the zero order artifact
          */
          zero_order_invalidation() : filter(init())
          {}
  
          zero_order_invalidation(filter f) :filter(f)
          {
              rs2_error* e = nullptr;
              if (!rs2_is_processing_block_extendable_to(f.get(), RS2_EXTENSION_ZERO_ORDER_FILTER, &e) && !e)
              {
                  _block.reset();
              }
              error::handle(e);
          }
  
      private:
          friend class context;
  
          std::shared_ptr<rs2_processing_block> init()
          {
              rs2_error* e = nullptr;
              auto block = std::shared_ptr<rs2_processing_block>(
                  rs2_create_zero_order_invalidation_block(&e),
                  rs2_delete_processing_block);
              error::handle(e);
  
              return block;
          }
      };
  
      class hole_filling_filter : public filter
      {
      public:
          /**
          * Create hole filling filter
          * The processing performed depends on the selected hole filling mode.
          */
          hole_filling_filter() : filter(init(), 1) {}
  
          /**
          * Create hole filling filter
          * The processing performed depends on the selected hole filling mode.
          * \param[in] mode - select the hole fill mode:
          * 0 - fill_from_left - Use the value from the left neighbor pixel to fill the hole
          * 1 - farest_from_around - Use the value from the neighboring pixel which is furthest away from the sensor
          * 2 - nearest_from_around - - Use the value from the neighboring pixel closest to the sensor
          */
          hole_filling_filter(int mode) : filter(init(), 1)
          {
              set_option(RS2_OPTION_HOLES_FILL, float(mode));
          }
  
          hole_filling_filter(filter f) :filter(f)
          {
              rs2_error* e = nullptr;
              if (!rs2_is_processing_block_extendable_to(f.get(), RS2_EXTENSION_HOLE_FILLING_FILTER, &e) && !e)
              {
                  _block.reset();
              }
              error::handle(e);
          }
      private:
          friend class context;
  
          std::shared_ptr<rs2_processing_block> init()
          {
              rs2_error* e = nullptr;
              auto block = std::shared_ptr<rs2_processing_block>(
                  rs2_create_hole_filling_filter_block(&e),
                  rs2_delete_processing_block);
              error::handle(e);
  
              // Redirect options API to the processing block
              //options::operator=(_block);
  
              return block;
          }
      };
  
      class rates_printer : public filter
      {
      public:
          /**
          * Create hole filling processing block
          * the processing perform the hole filling base on different hole filling mode.
          */
          rates_printer() : filter(init(), 1) {}
  
      private:
          friend class context;
  
          std::shared_ptr<rs2_processing_block> init()
          {
              rs2_error* e = nullptr;
              auto block = std::shared_ptr<rs2_processing_block>(
                  rs2_create_rates_printer_block(&e),
                  rs2_delete_processing_block);
              error::handle(e);
  
              return block;
          }
      };
  }
  #endif // LIBREALSENSE_RS2_PROCESSING_HPP
  