HW2 Submission -- Code Changes

R2Image.cpp

void R2Image::
SobelX(void)
{
	R2Image *output = new R2Image(width, height);

  double sobel_x[3][3] = {
    {-1, 0, 1},
    {-2, 0, 2},
    {-1, 0, 1}
  };

  for (int i = 1; i < width-1; i++) {
    for (int j = 1;  j < height-1; j++) {
      double sobelVal =
        (sobel_x[0][0] * Pixel(i-1,j-1).Luminance()) + (sobel_x[0][1] * Pixel(i,j-1).Luminance()) + (sobel_x[0][2] * Pixel(i+1,j-1).Luminance()) +
        (sobel_x[1][0] * Pixel(i-1,j).Luminance())   + (sobel_x[1][1] * Pixel(i,j).Luminance())   + (sobel_x[1][2] * Pixel(i+1,j).Luminance()) +
        (sobel_x[2][0] * Pixel(i-1,j+1).Luminance()) + (sobel_x[2][1] * Pixel(i,j+1).Luminance()) + (sobel_x[2][2] * Pixel(i+1,j+1).Luminance());

      sobelVal = (sobelVal + 1) / 2;

      R2Pixel *newPixel = new R2Pixel(sobelVal, sobelVal, sobelVal, 1);
      newPixel->Clamp();
      output->SetPixel(i, j, *newPixel);
    }
  }

  this->pixels = output->pixels;
  output->pixels = nullptr;
  delete output;
}

void R2Image::
SobelY(void)
{
	R2Image *output = new R2Image(width, height);

  double sobel_y[3][3] = {
    {-1, -2, -1},
    {0, 0, 0},
    {1, 2, 1}
  };

  for (int i = 1; i < width-1; i++) {
    for (int j = 1;  j < height-1; j++) {
      double sobelVal =
        (sobel_y[0][0] * Pixel(i-1,j-1).Luminance()) + (sobel_y[0][1] * Pixel(i,j-1).Luminance()) + (sobel_y[0][2] * Pixel(i+1,j-1).Luminance()) +
        (sobel_y[1][0] * Pixel(i-1,j).Luminance())   + (sobel_y[1][1] * Pixel(i,j).Luminance())   + (sobel_y[1][2] * Pixel(i+1,j).Luminance()) +
        (sobel_y[2][0] * Pixel(i-1,j+1).Luminance()) + (sobel_y[2][1] * Pixel(i,j+1).Luminance()) + (sobel_y[2][2] * Pixel(i+1,j+1).Luminance());

      sobelVal = (sobelVal + 1) / 2;

      R2Pixel *newPixel = new R2Pixel(sobelVal, sobelVal, sobelVal, 1);
      newPixel->Clamp();
      output->SetPixel(i, j, *newPixel);
    }
  }

  this->pixels = output->pixels;
  output->pixels = nullptr;
  delete output;
}

void R2Image::
ChangeSaturation(double factor)
{
  // http://www.niwa.nu/2013/05/math-behind-colorspace-conversions-rgb-hsl/

  for (int i = 0; i < width; i++) {
    for (int j = 0;  j < height; j++) {
      R2Pixel p = Pixel(i,j);

      // convert RGB triplet to HSL triplet
      double h, s, l;
      double r = p.Red(), g = p.Green(), b = p.Blue();
      double r2, g2, b2;
      double min = std::min(r, std::min(g, b));
      double max = std::max(r, std::max(g, b));

      l = p.Luminance();

      if(l < 0.5) {
        s = (max-min)/(max+min);
      } else {
        s = (max-min)/(2.0-max-min);
      }

      if(isnan(s)) {s=0;}

      if(min == max) {
        h = 0;
      } else {
        if(max == r) {h = (g-b)/(max-min);}
        else if(max == g) {h = 2.0 + (b-r)/(max-min);}
        else if(max == b) {h = 4.0 + (r-g)/(max-min);}
        else {h = 0;}
        h /= 6;
      }

      h = h>1?1:h<0?0:h;
      s = s>1?1:s<0?0:s;
      l = l>1?1:l<0?0:l;

      // Change saturation by factor
      s *= factor;

      // HSL back to RGB
      double t1, t2, tr, tg, tb;
      if(s == 0) {
        r2 = l; g2 = l; b2 = l;
      } else {
        if(l < 0.5) {
          t1 = l * (1.0+s);
        } else {
          t1 = l+s-l*s;
        }

        t2 = 2.0 * l - t1;
        tr = fmod(h + 0.333, 1);
        tg = fmod(h, 1);
        tb = fmod(h - 0.333, 1);

        if(6*tr < 1) {r2 = t2 + (t1 - t2) * 6 * tr;}
        else if(2*tr < 1) {r2 = t1;}
        else if(3*tr < 2) {r2 = t2 + (t1-t2) * (0.666-tr) * 6;}
        else {r2 = t2;}

        if(6*tg < 1) {g2 = t2 + (t1 - t2) * 6 * tg;}
        else if(2*tg < 1) {g2 = t1;}
        else if(3*tg < 2) {g2 = t2 + (t1-t2) * (0.666-tg) * 6;}
        else {g2 = t2;}

        if(6*tb < 1) {b2 = t2 + (t1 - t2) * 6 * tb;}
        else if(2*tb < 1) {b2 = t1;}
        else if(3*tb < 2) {b2 = t2 + (t1-t2) * (0.666-tb) * 6;}
        else {b2 = t2;}
      }

      Pixel(i, j).Reset(r2, g2, b2, 1);
      Pixel(i, j).Clamp();
    }
  }
}

void R2Image::
Sharpen()
{
  R2Image *output = new R2Image(width, height);

  double sharpen[3][3] = {
    {-2, -2, -2},
    {-2, 16, -2},
    {-2, -2, -2}
  };

  for (int i = 1; i < width-1; i++) {
    for (int j = 1;  j < height-1; j++) {

      double sharpenR =
        (sharpen[0][0] * Pixel(i-1,j-1).Red()) + (sharpen[0][1] * Pixel(i,j-1).Red()) + (sharpen[0][2] * Pixel(i+1,j-1).Red()) +
        (sharpen[1][0] * Pixel(i-1,j).Red())   + (sharpen[1][1] * Pixel(i,j).Red())   + (sharpen[1][2] * Pixel(i+1,j).Red()) +
        (sharpen[2][0] * Pixel(i-1,j+1).Red()) + (sharpen[2][1] * Pixel(i,j+1).Red()) + (sharpen[2][2] * Pixel(i+1,j+1).Red());

      double sharpenG =
        (sharpen[0][0] * Pixel(i-1,j-1).Green()) + (sharpen[0][1] * Pixel(i,j-1).Green()) + (sharpen[0][2] * Pixel(i+1,j-1).Green()) +
        (sharpen[1][0] * Pixel(i-1,j).Green())   + (sharpen[1][1] * Pixel(i,j).Green())   + (sharpen[1][2] * Pixel(i+1,j).Green()) +
        (sharpen[2][0] * Pixel(i-1,j+1).Green()) + (sharpen[2][1] * Pixel(i,j+1).Green()) + (sharpen[2][2] * Pixel(i+1,j+1).Green());

      double sharpenB =
        (sharpen[0][0] * Pixel(i-1,j-1).Blue()) + (sharpen[0][1] * Pixel(i,j-1).Blue()) + (sharpen[0][2] * Pixel(i+1,j-1).Blue()) +
        (sharpen[1][0] * Pixel(i-1,j).Blue())   + (sharpen[1][1] * Pixel(i,j).Blue())   + (sharpen[1][2] * Pixel(i+1,j).Blue()) +
        (sharpen[2][0] * Pixel(i-1,j+1).Blue()) + (sharpen[2][1] * Pixel(i,j+1).Blue()) + (sharpen[2][2] * Pixel(i+1,j+1).Blue());

      R2Pixel *newPixel = new R2Pixel(Pixel(i, j).Red() + sharpenR / 2,
        Pixel(i, j).Green() + sharpenG / 2, Pixel(i, j).Blue() + sharpenB / 2, 1);
      newPixel->Clamp();
      output->SetPixel(i, j, *newPixel);
    }
  }

  this->pixels = output->pixels;
  output->pixels = nullptr;
  delete output;
}