usPostScanToPreScan2DConverter.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 <visp3/ustk_core/usPostScanToPreScan2DConverter.h>
 
//#include <visp/vpMath.h>
usPostScanToPreScan2DConverter::usPostScanToPreScan2DConverter() : m_isInit(false) {}
 
usPostScanToPreScan2DConverter::usPostScanToPreScan2DConverter(const usImagePostScan2D<unsigned char> &inputSettings,
                                                               const int BModeSampleNumber, const int scanLineNumber)
{
  init(inputSettings, BModeSampleNumber, scanLineNumber);
}
 
usPostScanToPreScan2DConverter::usPostScanToPreScan2DConverter(const usTransducerSettings &transducerSettings,
                                                               const int BModeSampleNumber, const int scanLineNumber,
                                                               const double xResolution, const double yResolution)
{
  init(transducerSettings, BModeSampleNumber, scanLineNumber, xResolution, yResolution);
}
 
usPostScanToPreScan2DConverter::~usPostScanToPreScan2DConverter() {}
 
void usPostScanToPreScan2DConverter::init(const usImagePostScan2D<unsigned char> &inputSettings,
                                          const int BModeSampleNumber, const int scanLineNumber)
{
  // check if init is necessary
  if (m_initSettings == (usTransducerSettings)inputSettings && m_xResolution == inputSettings.getWidthResolution() &&
      m_yResolution == inputSettings.getHeightResolution() && m_scanLineNumber == scanLineNumber &&
      m_BModeSampleNumber == BModeSampleNumber) {
    return;
  }
 
  // check resolution to avoir errors
  if (inputSettings.getHeightResolution() == 0.0 || inputSettings.getWidthResolution() == 0.0)
    throw(vpException(vpException::notInitialized, "Please fill the post-scan resplution before init the conversion."));
 
  // convex transducer scan conversion
  if (inputSettings.isTransducerConvex()) {
    double APitch = inputSettings.getDepth() / (double)(BModeSampleNumber);
    double LPitch = inputSettings.getScanLinePitch() * inputSettings.getTransducerRadius();
 
    double r_min = inputSettings.getTransducerRadius();
    double r_max = (inputSettings.getTransducerRadius() + APitch * BModeSampleNumber);
    double t_min = -inputSettings.getFieldOfView() / 2.0;
    // 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_iMap.resize(BModeSampleNumber, scanLineNumber);
    m_jMap.resize(BModeSampleNumber, scanLineNumber);
 
    double r, t;
    for (int u = 0; u < BModeSampleNumber; ++u) {
      for (int v = 0; v < scanLineNumber; ++v) {
        r = inputSettings.getTransducerRadius() + APitch * u;
        t = (v - (scanLineNumber - 1) / 2.0) * LPitch / inputSettings.getTransducerRadius();
        m_iMap[u][v] = (r * cos(t) - x_min) / inputSettings.getHeightResolution(); // resolution to check
        m_jMap[u][v] = (r * sin(t) - y_min) / inputSettings.getWidthResolution();  // resolution to check
      }
    }
    m_isInit = true;
  }
  // linear transducer scan-conversion
  else {
    throw(vpException(vpException::notImplementedError,
                      "Back-scan conversion is not implemented for linear transducer."));
  }
  // saving settings
  m_initSettings = inputSettings;
  m_xResolution = inputSettings.getWidthResolution();
  m_yResolution = inputSettings.getHeightResolution();
  m_scanLineNumber = scanLineNumber;
  m_BModeSampleNumber = BModeSampleNumber;
}
 
void usPostScanToPreScan2DConverter::init(const usTransducerSettings &transducerSettings, const int BModeSampleNumber,
                                          const int scanLineNumber, const double xResolution, const double yResolution)
{
  // check if init is necessary
  if (m_initSettings == transducerSettings && m_xResolution == xResolution && m_yResolution == yResolution &&
      m_scanLineNumber == scanLineNumber && m_BModeSampleNumber == BModeSampleNumber) {
    return;
  }
 
  // convex transducer scan conversion
  if (transducerSettings.isTransducerConvex()) {
    double APitch = transducerSettings.getDepth() / BModeSampleNumber;
    double LPitch =
        transducerSettings.getFieldOfView() * transducerSettings.getTransducerRadius() / (scanLineNumber - 1);
 
    double r_min = transducerSettings.getTransducerRadius();
    double r_max = (transducerSettings.getTransducerRadius() + APitch * BModeSampleNumber);
    double t_min = -transducerSettings.getFieldOfView() / 2.0;
    // 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_iMap.resize(BModeSampleNumber, scanLineNumber);
    m_jMap.resize(BModeSampleNumber, scanLineNumber);
 
    double r, t;
    for (int u = 0; u < BModeSampleNumber; ++u) {
      for (int v = 0; v < scanLineNumber; ++v) {
        r = transducerSettings.getTransducerRadius() + APitch * u;
        t = (v - (scanLineNumber - 1) / 2.0) * LPitch / transducerSettings.getTransducerRadius();
        m_iMap[u][v] = (r * cos(t) - x_min) / yResolution; // to check
        m_jMap[u][v] = (r * sin(t) - y_min) / xResolution; // to check
      }
    }
    m_isInit = true;
  }
  // linear transducer scan-conversion
  else {
    // not implemented
  }
  // saving settings
  m_initSettings = transducerSettings;
  m_xResolution = xResolution;
  m_yResolution = yResolution;
  m_scanLineNumber = scanLineNumber;
  m_BModeSampleNumber = BModeSampleNumber;
}
 
void usPostScanToPreScan2DConverter::convert(const usImagePostScan2D<unsigned char> &imageToConvert,
                                             usImagePreScan2D<unsigned char> &imageConverted, int preScanSamples)
{
  if (!m_isInit) {
    init(imageToConvert, preScanSamples, imageToConvert.getScanLineNumber());
  }
 
  imageConverted.setImagePreScanSettings(usImagePreScanSettings(m_initSettings, m_yResolution));
 
  imageConverted.setScanLineNumber(m_scanLineNumber);
  imageConverted.setFieldOfView(m_initSettings.getFieldOfView());
  imageConverted.setAxialResolution(m_initSettings.getDepth() / m_BModeSampleNumber);
  imageConverted.setTransducerConvexity(m_initSettings.isTransducerConvex());
  imageConverted.setTransducerRadius(m_initSettings.getTransducerRadius());
 
  imageConverted.resize(m_BModeSampleNumber, m_scanLineNumber);
  double i, j;
  for (unsigned int u = 0; u < imageConverted.getBModeSampleNumber(); ++u)
    for (unsigned int v = 0; v < imageConverted.getScanLineNumber(); ++v) {
      i = m_iMap[u][v];
      j = m_jMap[u][v];
      imageConverted[u][v] = static_cast<unsigned char>(interpolateLinear(imageToConvert, i, j));
    }
}
 
double usPostScanToPreScan2DConverter::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;
}