vpImgproc.cpp

/****************************************************************************
 *
 * This file is part of the ViSP software.
 * Copyright (C) 2005 - 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 as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * See the file LICENSE.txt at the root directory of this source
 * distribution for additional information about the GNU GPL.
 *
 * For using ViSP with software that can not be combined with the GNU
 * GPL, please contact Inria about acquiring a ViSP Professional
 * Edition License.
 *
 * See http://visp.inria.fr for more information.
 *
 * 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 visp@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.
 *
 * Description:
 * Convert image types.
 *
 * Authors:
 * Souriya Trinh
 *
 *****************************************************************************/
/* Autostretch HSV 0.10 --- image filter plug-in for GIMP
 *
 * Copyright (C) 1997 Scott Goehring
 * Copyright (C) 1996 Federico Mena Quintero
 *
 * You can contact me at scott@poverty.bloomington.in.us
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <visp3/core/vpHistogram.h>
#include <visp3/core/vpImageConvert.h>
#include <visp3/core/vpImageFilter.h>
#include <visp3/core/vpMath.h>
#include <visp3/imgproc/vpImgproc.h>

void vp::adjust(vpImage<unsigned char> &I, const double alpha, const double beta)
{
  // Construct the look-up table
  unsigned char lut[256];
  for (unsigned int i = 0; i < 256; i++) {
    lut[i] = vpMath::saturate<unsigned char>(alpha * i + beta);
  }

  // Apply the transformation using a LUT
  I.performLut(lut);
}

void vp::adjust(const vpImage<unsigned char> &I1, vpImage<unsigned char> &I2, const double alpha, const double beta)
{
  // Copy I1 to I2
  I2 = I1;

  vp::adjust(I2, alpha, beta);
}

void vp::adjust(vpImage<vpRGBa> &I, const double alpha, const double beta)
{
  // Construct the look-up table
  vpRGBa lut[256];
  for (unsigned int i = 0; i < 256; i++) {
    lut[i].R = vpMath::saturate<unsigned char>(alpha * i + beta);
    lut[i].G = vpMath::saturate<unsigned char>(alpha * i + beta);
    lut[i].B = vpMath::saturate<unsigned char>(alpha * i + beta);
    lut[i].A = vpMath::saturate<unsigned char>(alpha * i + beta);
  }

  // Apply the transformation using a LUT
  I.performLut(lut);
}

void vp::adjust(const vpImage<vpRGBa> &I1, vpImage<vpRGBa> &I2, const double alpha, const double beta)
{
  // Copy I1 to I2
  I2 = I1;

  vp::adjust(I2, alpha, beta);
}

void vp::equalizeHistogram(vpImage<unsigned char> &I)
{
  if (I.getWidth() * I.getHeight() == 0) {
    return;
  }

  // Calculate the histogram
  vpHistogram hist;
  hist.calculate(I);

  // Calculate the cumulative distribution function
  unsigned int cdf[256];
  unsigned int cdfMin = /*std::numeric_limits<unsigned int>::max()*/ UINT_MAX, cdfMax = 0;
  unsigned int minValue =
                   /*std::numeric_limits<unsigned int>::max()*/ UINT_MAX,
               maxValue = 0;
  cdf[0] = hist[0];

  if (cdf[0] < cdfMin && cdf[0] > 0) {
    cdfMin = cdf[0];
    minValue = 0;
  }

  for (unsigned int i = 1; i < 256; i++) {
    cdf[i] = cdf[i - 1] + hist[i];

    if (cdf[i] < cdfMin && cdf[i] > 0) {
      cdfMin = cdf[i];
      minValue = i;
    }

    if (cdf[i] > cdfMax) {
      cdfMax = cdf[i];
      maxValue = i;
    }
  }

  unsigned int nbPixels = I.getWidth() * I.getHeight();
  if (nbPixels == cdfMin) {
    // Only one brightness value in the image
    return;
  }

  // Construct the look-up table
  unsigned char lut[256];
  for (unsigned int x = minValue; x <= maxValue; x++) {
    lut[x] = vpMath::round((cdf[x] - cdfMin) / (double)(nbPixels - cdfMin) * 255.0);
  }

  I.performLut(lut);
}

void vp::equalizeHistogram(const vpImage<unsigned char> &I1, vpImage<unsigned char> &I2)
{
  I2 = I1;
  vp::equalizeHistogram(I2);
}

void vp::equalizeHistogram(vpImage<vpRGBa> &I, const bool useHSV)
{
  if (I.getWidth() * I.getHeight() == 0) {
    return;
  }

  if (!useHSV) {
    // Split the RGBa image into 4 images
    vpImage<unsigned char> pR(I.getHeight(), I.getWidth());
    vpImage<unsigned char> pG(I.getHeight(), I.getWidth());
    vpImage<unsigned char> pB(I.getHeight(), I.getWidth());
    vpImage<unsigned char> pa(I.getHeight(), I.getWidth());

    vpImageConvert::split(I, &pR, &pG, &pB, &pa);

    // Apply histogram equalization for each channel
    vp::equalizeHistogram(pR);
    vp::equalizeHistogram(pG);
    vp::equalizeHistogram(pB);

    // Merge the result in I
    unsigned int size = I.getWidth() * I.getHeight();
    unsigned char *ptrStart = (unsigned char *)I.bitmap;
    unsigned char *ptrEnd = ptrStart + size * 4;
    unsigned char *ptrCurrent = ptrStart;

    unsigned int cpt = 0;
    while (ptrCurrent != ptrEnd) {
      *ptrCurrent = pR.bitmap[cpt];
      ++ptrCurrent;

      *ptrCurrent = pG.bitmap[cpt];
      ++ptrCurrent;

      *ptrCurrent = pB.bitmap[cpt];
      ++ptrCurrent;

      *ptrCurrent = pa.bitmap[cpt];
      ++ptrCurrent;

      cpt++;
    }
  } else {
    vpImage<unsigned char> hue(I.getHeight(), I.getWidth());
    vpImage<unsigned char> saturation(I.getHeight(), I.getWidth());
    vpImage<unsigned char> value(I.getHeight(), I.getWidth());

    unsigned int size = I.getWidth() * I.getHeight();
    // Convert from RGBa to HSV
    vpImageConvert::RGBaToHSV((unsigned char *)I.bitmap, (unsigned char *)hue.bitmap,
                              (unsigned char *)saturation.bitmap, (unsigned char *)value.bitmap, size);

    // Histogram equalization on the value plane
    vp::equalizeHistogram(value);

    // Convert from HSV to RGBa
    vpImageConvert::HSVToRGBa((unsigned char *)hue.bitmap, (unsigned char *)saturation.bitmap,
                              (unsigned char *)value.bitmap, (unsigned char *)I.bitmap, size);
  }
}

void vp::equalizeHistogram(const vpImage<vpRGBa> &I1, vpImage<vpRGBa> &I2, const bool useHSV)
{
  I2 = I1;
  vp::equalizeHistogram(I2, useHSV);
}

void vp::gammaCorrection(vpImage<unsigned char> &I, const double gamma)
{
  double inverse_gamma = 1.0;
  if (gamma > 0) {
    inverse_gamma = 1.0 / gamma;
  } else {
    throw vpException(vpException::badValue, "The gamma value must be positive !");
  }

  // Construct the look-up table
  unsigned char lut[256];
  for (unsigned int i = 0; i < 256; i++) {
    lut[i] = vpMath::saturate<unsigned char>(pow((double)i / 255.0, inverse_gamma) * 255.0);
  }

  I.performLut(lut);
}

void vp::gammaCorrection(const vpImage<unsigned char> &I1, vpImage<unsigned char> &I2, const double gamma)
{
  I2 = I1;
  vp::gammaCorrection(I2, gamma);
}

void vp::gammaCorrection(vpImage<vpRGBa> &I, const double gamma)
{
  double inverse_gamma = 1.0;
  if (gamma > 0) {
    inverse_gamma = 1.0 / gamma;
  } else {
    throw vpException(vpException::badValue, "The gamma value must be positive !");
  }

  // Construct the look-up table
  vpRGBa lut[256];
  for (unsigned int i = 0; i < 256; i++) {
    lut[i].R = vpMath::saturate<unsigned char>(pow((double)i / 255.0, inverse_gamma) * 255.0);
    lut[i].G = vpMath::saturate<unsigned char>(pow((double)i / 255.0, inverse_gamma) * 255.0);
    lut[i].B = vpMath::saturate<unsigned char>(pow((double)i / 255.0, inverse_gamma) * 255.0);
    lut[i].A = vpMath::saturate<unsigned char>(pow((double)i / 255.0, inverse_gamma) * 255.0);
  }

  I.performLut(lut);
}

void vp::gammaCorrection(const vpImage<vpRGBa> &I1, vpImage<vpRGBa> &I2, const double gamma)
{
  I2 = I1;
  vp::gammaCorrection(I2, gamma);
}

void vp::stretchContrast(vpImage<unsigned char> &I)
{
  // Find min and max intensity values
  unsigned char min = 255, max = 0;
  I.getMinMaxValue(min, max);

  unsigned char range = max - min;

  // Construct the look-up table
  unsigned char lut[256];
  if (range > 0) {
    for (unsigned int x = min; x <= max; x++) {
      lut[x] = 255 * (x - min) / range;
    }
  } else {
    lut[min] = min;
  }

  I.performLut(lut);
}

void vp::stretchContrast(const vpImage<unsigned char> &I1, vpImage<unsigned char> &I2)
{
  // Copy I1 to I2
  I2 = I1;
  vp::stretchContrast(I2);
}

void vp::stretchContrast(vpImage<vpRGBa> &I)
{
  // Find min and max intensity values
  vpRGBa min = 255, max = 0;

  // Split the RGBa image into 4 images
  vpImage<unsigned char> pR(I.getHeight(), I.getWidth());
  vpImage<unsigned char> pG(I.getHeight(), I.getWidth());
  vpImage<unsigned char> pB(I.getHeight(), I.getWidth());
  vpImage<unsigned char> pa(I.getHeight(), I.getWidth());

  vpImageConvert::split(I, &pR, &pG, &pB, &pa);
  // Min max values calculated for each channel
  unsigned char minChannel, maxChannel;
  pR.getMinMaxValue(minChannel, maxChannel);
  min.R = minChannel;
  max.R = maxChannel;

  pG.getMinMaxValue(minChannel, maxChannel);
  min.G = minChannel;
  max.G = maxChannel;

  pB.getMinMaxValue(minChannel, maxChannel);
  min.B = minChannel;
  max.B = maxChannel;

  pa.getMinMaxValue(minChannel, maxChannel);
  min.A = minChannel;
  max.A = maxChannel;

  // Construct the look-up table
  vpRGBa lut[256];
  unsigned char rangeR = max.R - min.R;
  if (rangeR > 0) {
    for (unsigned int x = min.R; x <= max.R; x++) {
      lut[x].R = 255 * (x - min.R) / rangeR;
    }
  } else {
    lut[min.R].R = min.R;
  }

  unsigned char rangeG = max.G - min.G;
  if (rangeG > 0) {
    for (unsigned int x = min.G; x <= max.G; x++) {
      lut[x].G = 255 * (x - min.G) / rangeG;
    }
  } else {
    lut[min.G].G = min.G;
  }

  unsigned char rangeB = max.B - min.B;
  if (rangeB > 0) {
    for (unsigned int x = min.B; x <= max.B; x++) {
      lut[x].B = 255 * (x - min.B) / rangeB;
    }
  } else {
    lut[min.B].B = min.B;
  }

  unsigned char rangeA = max.A - min.A;
  if (rangeA > 0) {
    for (unsigned int x = min.A; x <= max.A; x++) {
      lut[x].A = 255 * (x - min.A) / rangeA;
    }
  } else {
    lut[min.A].A = min.A;
  }

  I.performLut(lut);
}

void vp::stretchContrast(const vpImage<vpRGBa> &I1, vpImage<vpRGBa> &I2)
{
  // Copy I1 to I2
  I2 = I1;
  vp::stretchContrast(I2);
}

void vp::stretchContrastHSV(vpImage<vpRGBa> &I)
{
  unsigned int size = I.getWidth() * I.getHeight();

  // Convert RGB to HSV
  vpImage<double> hueImage(I.getHeight(), I.getWidth()), saturationImage(I.getHeight(), I.getWidth()),
      valueImage(I.getHeight(), I.getWidth());
  vpImageConvert::RGBaToHSV((unsigned char *)I.bitmap, hueImage.bitmap, saturationImage.bitmap, valueImage.bitmap,
                            size);

  // Find min and max Saturation and Value
  double minSaturation, maxSaturation, minValue, maxValue;
  saturationImage.getMinMaxValue(minSaturation, maxSaturation);
  valueImage.getMinMaxValue(minValue, maxValue);

  double *ptrStart = saturationImage.bitmap;
  double *ptrEnd = saturationImage.bitmap + size;
  double *ptrCurrent = ptrStart;

  // Stretch Saturation
  if (maxSaturation - minSaturation > 0.0) {
    while (ptrCurrent != ptrEnd) {
      *ptrCurrent = (*ptrCurrent - minSaturation) / (maxSaturation - minSaturation);
      ++ptrCurrent;
    }
  }

  // Stretch Value
  if (maxValue - minValue > 0.0) {
    ptrStart = valueImage.bitmap;
    ptrEnd = valueImage.bitmap + size;
    ptrCurrent = ptrStart;

    while (ptrCurrent != ptrEnd) {
      *ptrCurrent = (*ptrCurrent - minValue) / (maxValue - minValue);
      ++ptrCurrent;
    }
  }

  // Convert HSV to RGBa
  vpImageConvert::HSVToRGBa(hueImage.bitmap, saturationImage.bitmap, valueImage.bitmap, (unsigned char *)I.bitmap,
                            size);
}

void vp::stretchContrastHSV(const vpImage<vpRGBa> &I1, vpImage<vpRGBa> &I2)
{
  // Copy I1 to I2
  I2 = I1;
  vp::stretchContrastHSV(I2);
}

void vp::unsharpMask(vpImage<unsigned char> &I, const unsigned int size, const double weight)
{
  if (weight < 1.0 && weight >= 0.0) {
    // Gaussian blurred image
    vpImage<double> I_blurred;
    vpImageFilter::gaussianBlur(I, I_blurred, size);

    // Unsharp mask
    for (unsigned int cpt = 0; cpt < I.getSize(); cpt++) {
      double val = (I.bitmap[cpt] - weight * I_blurred.bitmap[cpt]) / (1 - weight);
      I.bitmap[cpt] = vpMath::saturate<unsigned char>(val); // val > 255 ? 255 : (val < 0 ? 0 : val);
    }
  }
}

void vp::unsharpMask(const vpImage<unsigned char> &I1, vpImage<unsigned char> &I2, const unsigned int size,
                     const double weight)
{
  // Copy I1 to I2
  I2 = I1;
  vp::unsharpMask(I2, size, weight);
}

void vp::unsharpMask(vpImage<vpRGBa> &I, const unsigned int size, const double weight)
{
  if (weight < 1.0 && weight >= 0.0) {
    // Gaussian blurred image
    vpImage<double> I_blurred_R, I_blurred_G, I_blurred_B;
    vpImage<unsigned char> I_R, I_G, I_B;

    vpImageConvert::split(I, &I_R, &I_G, &I_B);
    vpImageFilter::gaussianBlur(I_R, I_blurred_R, size);
    vpImageFilter::gaussianBlur(I_G, I_blurred_G, size);
    vpImageFilter::gaussianBlur(I_B, I_blurred_B, size);

    // Unsharp mask
    for (unsigned int cpt = 0; cpt < I.getSize(); cpt++) {
      double val_R = (I.bitmap[cpt].R - weight * I_blurred_R.bitmap[cpt]) / (1 - weight);
      double val_G = (I.bitmap[cpt].G - weight * I_blurred_G.bitmap[cpt]) / (1 - weight);
      double val_B = (I.bitmap[cpt].B - weight * I_blurred_B.bitmap[cpt]) / (1 - weight);

      I.bitmap[cpt].R = vpMath::saturate<unsigned char>(val_R);
      I.bitmap[cpt].G = vpMath::saturate<unsigned char>(val_G);
      I.bitmap[cpt].B = vpMath::saturate<unsigned char>(val_B);
    }
  }
}

void vp::unsharpMask(const vpImage<vpRGBa> &I1, vpImage<vpRGBa> &I2, const unsigned int size, const double weight)
{
  // Copy I1 to I2
  I2 = I1;
  vp::unsharpMask(I2, size, weight);
}