vx_training_07.cc

/* Copyright (C) 2022 RidgeRun, LLC (http://www.ridgerun.com)
 * All Rights Reserved.
 *
 * The contents of this software are proprietary and confidential to RidgeRun,
 * LLC.  No part of this program may be photocopied, reproduced or translated
 * into another programming language without prior written consent of
 * RidgeRun, LLC.  The user is free to modify the source code after obtaining
 * a software license from RidgeRun.  All source code changes must be provided
 * back to RidgeRun without any encumbrance.
 */

#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"

#define STB_IMAGE_WRITE_IMPLEMENTATION
#include "stb_image_write.h"

#include <cmath>
#include <iostream>
#include <memory>
#include <opencv2/opencv.hpp>
#include <vector>
#include <VX/vx.h>

template<typename T>
static std::shared_ptr<T>
smart_ref (T *ptr)
{
  return std::shared_ptr<T> (ptr, [](T *ptr) {
    vxReleaseReference ((vx_reference *)&ptr);
  });
}

static int
populate_image (vx_image image, const unsigned char *img_data)
{
  int ret = -1;

  vx_uint32 width = 0;
  vx_uint32 height = 0;
  vx_int32 channels = 3;
  vxQueryImage (image, VX_IMAGE_WIDTH, &width, sizeof (width));
  vxQueryImage (image, VX_IMAGE_WIDTH, &height, sizeof (height));

  vx_imagepatch_addressing_t layout = { width, height, channels,
    static_cast<vx_int32>(width*channels), 0, 0, 0, 0 };
  
  const vx_rectangle_t rect = { 0, 0, width, height };

  vx_status status = vxCopyImagePatch (image, &rect, 0, &layout, (void *)img_data,
      VX_WRITE_ONLY, VX_MEMORY_TYPE_HOST);
  if (VX_SUCCESS != status) {
    std::cerr << "vx-training: Unable to copy data into image: " << status << std::endl;
    ret = -1;
  } else {
    ret = 0;
  }

  return ret;
}

static int
show_image (vx_image image)
{
  int ret = -1;

  vx_uint32 width = 0;
  vx_uint32 height = 0;
  vxQueryImage (image, VX_IMAGE_WIDTH, &width, sizeof (width));
  vxQueryImage (image, VX_IMAGE_WIDTH, &height, sizeof (height));

  const vx_rectangle_t rect = { 0, 0, width, height };
  vx_uint32 plane = 0;
  vx_map_id map_id = 0;
  vx_imagepatch_addressing_t addr =  { 0 };
  unsigned char *ptr = 0;
  vx_enum usage = VX_READ_ONLY;
  vx_enum mem_type = VX_MEMORY_TYPE_HOST;
  vx_uint32 flags = VX_NOGAP_X;
  vx_status status = vxMapImagePatch (image, &rect, plane, &map_id, &addr, (void **)&ptr, usage, mem_type, flags);
  if (VX_SUCCESS != status) {
    std::cerr << "vx-training: Unable to map image for reading:" << status << std::endl;
    ret = -1;
  } else {
    cv::Mat mat (height, width, CV_8UC1, ptr, addr.stride_y);
    cv::imshow ("Processed image", mat);
    ret = 0;
  }

  vxUnmapImagePatch (image, map_id);

  return ret;
}

static void VX_CALLBACK
context_log_callback(vx_context context, vx_reference ref, vx_status status,
    const vx_char string[])
{
  std::cout << "vx-training [dbg]: " << string << std::endl;
}

int
main (int argc, char *argv[])
{
  const char *filename = "lena.png";
  if (argc >= 2) {
    filename = argv[1];
  }

  const char *outname = "out.png";
  if (argc >= 3) {
    outname = argv[2];
  }
  
  auto context = smart_ref (vxCreateContext ());

  vx_status status = vxGetStatus ((vx_reference)context.get ());
  if (VX_SUCCESS != status) {
    std::cerr << "vx-training: Unable to create context:" << status << std::endl;
    return -1;
  }

  vx_bool reentrant = vx_false_e;
  vxRegisterLogCallback(context.get (), context_log_callback, reentrant);

  int width = 0;
  int height = 0;
  int channels = 0;
  auto img_data = std::shared_ptr<unsigned char>(stbi_load (filename, &width, &height, &channels, 3), free);
  if (NULL == img_data) {
    std::cerr << "vx-training: Unable to load image " << filename << std::endl;
    return -1;
  }
  
  auto in_image = smart_ref(vxCreateImage(context.get (), width, height, VX_DF_IMAGE_RGB));

  status = vxGetStatus ((vx_reference)in_image.get ());
  if (VX_SUCCESS != status) {
    std::cerr << "vx-training: Unable to create input image: " << status << std::endl;
    return -1;
  }

  if (0 != populate_image (in_image.get (), img_data.get ())) {
    std::cerr << "vx-training: Unable to populate image" << std::endl;
    return -1;
  }

  auto out_image = smart_ref(vxCreateImage(context.get (), width, height, VX_DF_IMAGE_U8));

  status = vxGetStatus ((vx_reference)out_image.get ());
  if (VX_SUCCESS != status) {
    std::cerr << "vx-training: Unable to create output image: " << status << std::endl;
    return -1;
  }

  auto graph = smart_ref (vxCreateGraph (context.get ()));

  status = vxGetStatus ((vx_reference)graph.get ());
  if (VX_SUCCESS != status) {
    std::cerr << "vx-training: Unable to create graph: " << status << std::endl;
    return -1;
  }

  auto intermediate = smart_ref (vxCreateVirtualImage(graph.get (), width, height, VX_DF_IMAGE_U8));

  status = vxGetStatus ((vx_reference)intermediate.get ());
  if (VX_SUCCESS != status) {
    std::cerr << "vx-training: Unable to create virtual image: " << status << std::endl;
    return -1;
  }

  auto matrix = smart_ref (vxCreateMatrix(context.get (), VX_TYPE_FLOAT32, 2, 3));
  vx_enum interpolation = VX_INTERPOLATION_BILINEAR;
  
  std::vector<std::shared_ptr<_vx_node>> nodes = {
    smart_ref (vxChannelExtractNode (graph.get (), in_image.get (), VX_CHANNEL_R, intermediate.get ())),
    smart_ref (vxWarpAffineNode (graph.get (), intermediate.get (), matrix.get (), interpolation, out_image.get ()))
  };

  for (auto &node: nodes) {
    status = vxGetStatus ((vx_reference)node.get ());
    if (VX_SUCCESS != status) {
      std::cerr << "vx-training: Unable to create processing node: " << status << std::endl;
      return -1;
    }
  }

  status = vxVerifyGraph (graph.get ());
  if (VX_SUCCESS != status) {
    std::cerr << "vx-training: Graph validation failed: " << status << std::endl;
    return -1;
  }

  cv::namedWindow ("Processed image", cv::WINDOW_AUTOSIZE);

  vx_float32 angle = 0.0;
  while (-1 == cv::waitKey(30)) {
    /*
      Images in OpenVX have the origin of the coordinate system in the
      upper left corner. Images will rotate around the origin. To rotate
      around the center we need to translate the image so that the origin
      matches the center, rotate, and translate back. In linear algebra,
      this is achieved by multiplying transformation matrices, were 
      they are applied from right to left.
      
          [1 0 w/2] [ cos(a) -sin(a) 0 ] [1 0 -w/2]
      R = [0 1 h/2] [ sin(a)  sin(a) 0 ] [0 1 -h/2]
          [0 0   1] [      0       0 1 ] [0 0    1]

          [ cos(a) -sin(a) -cos(a)*w/2 + sin(a)*h/2 + w/2 ]
      R = [ sin(a)  sin(a) -cos(a)*h/2 - sin(a)*h/2 + h/2 ]
    	  [      0       0                              1 ]
    */
    vx_float32 rad = angle*M_PI/180.0;
    angle++;
    /* Rotation only matrix */
    //vx_float32 mat[3][2] = {
    //  {cos (rad), sin (rad)},
    //  {-sin (rad), cos (rad)},
    //  {0, 0},
    //};
    
    /* Translate + rotate + translate back */
    vx_float32 mat[3][2] = {
      {cos (rad), sin (rad)},
      {-sin (rad), cos (rad)},
      {-cos (rad)*width/2 + sin (rad)*height/2 + width/2, -cos (rad)*height/2 - sin (rad)*width/2 + height/2},
    };
    vxCopyMatrix(matrix.get (), mat, VX_WRITE_ONLY, VX_MEMORY_TYPE_HOST);

    status = vxProcessGraph (graph.get ());
    if (VX_SUCCESS != status) {
      std::cerr << "vx-training: Error processing the graph: " << status << std::endl;
      return -1;
    }
    
    if (0 != show_image (out_image.get ())) {
      std::cerr << "vx-training: Error displayingoutput image" << std::endl;
      return -1;
    }
  }

  cv::destroyAllWindows ();

  return 0;
}