usPreScanToPostScan2DConverter.cpp

/****************************************************************************
 *
 * This file is part of the ustk software.
 * Copyright (C) 2016 - 2017 by Inria. All rights reserved.
 *
 * This software is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * ("GPL") version 2 as published by the Free Software Foundation.
 * See the file LICENSE.txt at the root directory of this source
 * distribution for additional information about the GNU GPL.
 *
 * For using ustk with software that can not be combined with the GNU
 * GPL, please contact Inria about acquiring a ViSP Professional
 * Edition License.
 *
 * This software was developed at:
 * Inria Rennes - Bretagne Atlantique
 * Campus Universitaire de Beaulieu
 * 35042 Rennes Cedex
 * France
 *
 * If you have questions regarding the use of this file, please contact
 * Inria at ustk@inria.fr
 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Authors:
 * Pierre Chatelain
 *
 *****************************************************************************/
 
#include <visp/vpMath.h>
#include <visp3/ustk_core/usPreScanToPostScan2DConverter.h>
 
usPreScanToPostScan2DConverter::usPreScanToPostScan2DConverter() : m_initDone(false) {}
 
usPreScanToPostScan2DConverter::~usPreScanToPostScan2DConverter() {}
 
void usPreScanToPostScan2DConverter::init(const usImagePostScan2D<unsigned char> &inputSettings,
                                          const int BModeSampleNumber, const int scanLineNumber)
{
  // check resolution to avoir errors
  if (inputSettings.getHeightResolution() == 0.0 || inputSettings.getWidthResolution() == 0.0)
    throw(vpException(vpException::notInitialized, "Please fill the post-scan resolution before init the conversion."));
 
  if (inputSettings.isTransducerConvex()) {
    m_scanLineNumber = scanLineNumber;
    m_BModeSampleNumber = BModeSampleNumber;
    m_xResolution = inputSettings.getWidthResolution();
    m_yResolution = inputSettings.getHeightResolution();
    m_settings = inputSettings;
 
    double APitch = inputSettings.getDepth() / (double)(BModeSampleNumber);
    double LPitch = inputSettings.getFieldOfView() * inputSettings.getTransducerRadius() / (double)(scanLineNumber - 1);
 
    double r_min = inputSettings.getTransducerRadius();
    double r_max = (inputSettings.getTransducerRadius() + APitch * BModeSampleNumber);
    double t_min = -((double)(scanLineNumber - 1) * LPitch) / (2.0 * inputSettings.getTransducerRadius());
    double t_max = -t_min;
    double x_min = r_min * cos(t_min);
    double x_max = r_max;
    double y_min = r_max * sin(t_min);
    double y_max = r_max * sin(t_max);
 
    m_height = vpMath::round((x_max - x_min) / m_yResolution);
    m_width = vpMath::round((y_max - y_min) / m_xResolution);
 
    m_rMap.resize(m_height, m_width);
    m_tMap.resize(m_height, m_width);
 
    double x, y;
    for (unsigned int i = 0; i < m_height; ++i) {
      for (unsigned int j = 0; j < m_width; ++j) {
        x = x_min + i * m_yResolution;
        y = y_min + j * m_xResolution;
        m_rMap[i][j] = (sqrt(x * x + y * y) - inputSettings.getTransducerRadius()) / APitch;
        m_tMap[i][j] = atan2(y, x) * inputSettings.getTransducerRadius() / LPitch + (scanLineNumber - 1) / 2.0;
      }
    }
  } else {
    m_scanLineNumber = scanLineNumber;
    m_BModeSampleNumber = BModeSampleNumber;
    m_xResolution = inputSettings.getWidthResolution();
    m_yResolution = inputSettings.getHeightResolution();
    m_settings = inputSettings;
 
    double APitch = inputSettings.getDepth() / (double)(BModeSampleNumber);
    m_height = vpMath::round((APitch * BModeSampleNumber) / m_yResolution);
    m_width = vpMath::round(inputSettings.getScanLinePitch() * (scanLineNumber - 1) / m_xResolution);
 
    m_rMap.resize(m_height, m_width);
    m_tMap.resize(m_height, m_width);
 
    for (unsigned int i = 0; i < m_height; ++i) {
      for (unsigned int j = 0; j < m_width; ++j) {
        m_rMap[i][j] = j;
        m_tMap[i][j] = i;
      }
    }
  }
 
  m_initDone = true;
}
 
void usPreScanToPostScan2DConverter::init(const usTransducerSettings &inputSettings, const int BModeSampleNumber,
                                          const int scanLineNumber, const double xResolution, const double yResolution)
{
  if (inputSettings.isTransducerConvex()) {
    m_scanLineNumber = scanLineNumber;
    m_BModeSampleNumber = BModeSampleNumber;
    m_xResolution = xResolution;
    m_yResolution = yResolution;
    m_settings = inputSettings;
 
    double APitch = inputSettings.getDepth() / (double)(BModeSampleNumber);
    double LPitch = inputSettings.getFieldOfView() * inputSettings.getTransducerRadius() / (double)(scanLineNumber - 1);
 
    double r_min = inputSettings.getTransducerRadius();
    double r_max = (inputSettings.getTransducerRadius() + APitch * BModeSampleNumber);
    double t_min = -((double)(scanLineNumber - 1) * LPitch) / (2.0 * inputSettings.getTransducerRadius());
    double t_max = -t_min;
    double x_min = r_min * cos(t_min);
    double x_max = r_max;
    double y_min = r_max * sin(t_min);
    double y_max = r_max * sin(t_max);
 
    m_height = vpMath::round((x_max - x_min) / m_yResolution);
    m_width = vpMath::round((y_max - y_min) / m_xResolution);
 
    m_rMap.resize(m_height, m_width);
    m_tMap.resize(m_height, m_width);
 
    double x, y;
    for (unsigned int i = 0; i < m_height; ++i) {
      for (unsigned int j = 0; j < m_width; ++j) {
        x = x_min + i * m_yResolution;
        y = y_min + j * m_xResolution;
        m_rMap[i][j] = (sqrt(x * x + y * y) - inputSettings.getTransducerRadius()) / APitch;
        m_tMap[i][j] = atan2(y, x) * inputSettings.getTransducerRadius() / LPitch + (scanLineNumber - 1) / 2.0;
      }
    }
  } else {
    m_scanLineNumber = scanLineNumber;
    m_BModeSampleNumber = BModeSampleNumber;
    m_xResolution = xResolution;
    m_yResolution = yResolution;
    m_settings = inputSettings;
 
    double APitch = inputSettings.getDepth() / (double)(BModeSampleNumber);
    m_height = vpMath::round(inputSettings.getDepth() / m_yResolution);
    m_width = vpMath::round(inputSettings.getScanLinePitch() * (scanLineNumber - 1) / m_xResolution);
 
    m_rMap.resize(m_height, m_width);
    m_tMap.resize(m_height, m_width);
 
    double ratio1 = m_xResolution / inputSettings.getScanLinePitch();
    double ratio2 = m_yResolution / APitch;
 
    for (unsigned int i = 0; i < m_height; ++i) {
      for (unsigned int j = 0; j < m_width; ++j) {
        m_rMap[i][j] = i * ratio2;
        m_tMap[i][j] = j * ratio1;
      }
    }
  }
 
  m_initDone = true;
}
 
void usPreScanToPostScan2DConverter::convert(const usImagePreScan2D<unsigned char> &preScanImage,
                                             usImagePostScan2D<unsigned char> &postScanImage, double xResolution,
                                             double yResolution)
{
  // if user specified the resolution wanted
  if (xResolution != 0. && yResolution != 0.) {
    init(preScanImage, preScanImage.getBModeSampleNumber(), preScanImage.getScanLineNumber(), xResolution, yResolution);
  }
 
  // check if init is done
  if (!m_initDone) {
    if (preScanImage.isTransducerConvex()) {
      double resolution = preScanImage.getAxialResolution();
      init(preScanImage, preScanImage.getBModeSampleNumber(), preScanImage.getScanLineNumber(), resolution, resolution);
    } else {
      init(preScanImage, preScanImage.getBModeSampleNumber(), preScanImage.getScanLineNumber(),
           preScanImage.getScanLinePitch(), preScanImage.getAxialResolution());
    }
  }
 
  postScanImage.resize(m_height, m_width);
  for (unsigned int i = 0; i < m_height; ++i)
    for (unsigned int j = 0; j < m_width; ++j) {
      double u = m_rMap[i][j];
      double v = m_tMap[i][j];
      postScanImage(i, j, (unsigned char)interpolateLinear(preScanImage, u, v));
    }
  // saving settings in postScanImage
  postScanImage.setHeightResolution(m_yResolution);
  postScanImage.setWidthResolution(m_xResolution);
  postScanImage.setScanLineNumber(m_scanLineNumber);
  postScanImage.setTransducerConvexity(preScanImage.isTransducerConvex());
  postScanImage.setScanLinePitch(m_settings.getScanLinePitch());
  postScanImage.setTransducerRadius(m_settings.getTransducerRadius());
  postScanImage.setDepth(m_settings.getDepth());
}
 
double usPreScanToPostScan2DConverter::interpolateLinear(const vpImage<unsigned char> &I, double x, double y)
{
  int x1 = (int)floor(x);
  int x2 = (int)ceil(x);
  int y1 = (int)floor(y);
  int y2 = (int)ceil(y);
 
  if ((0 <= x) && (x < I.getHeight()) && (0 <= y) && (y < I.getWidth())) {
    double val1, val2;
    // Check whether the indices are within the image extent
    if (x1 < 0)
      ++x1;
    if (y1 < 0)
      ++y1;
    if (x2 >= static_cast<int>(I.getHeight()))
      --x2;
    if (y2 >= static_cast<int>(I.getWidth()))
      --y2;
 
    // Check whether the target is on the grid
    if (x1 == x2) {
      val1 = I(x1, y1);
      val2 = I(x1, y2);
    } else {
      val1 = (x2 - x) * I(x1, y1) + (x - x1) * I(x2, y1);
      val2 = (x2 - x) * I(x1, y2) + (x - x1) * I(x2, y2);
    }
    if (y1 == y2)
      return val1;
    else
      return (y2 - y) * val1 + (y - y1) * val2;
  }
  return 0.0;
}