Exemple #1
0
void otsuThresholding(png::image<png::gray_pixel> & image)
{
  const int numPixels = image.get_width() * image.get_height();
  const size_t maxPixelValue = static_cast<size_t>(
        std::numeric_limits<png::gray_pixel>::max());

  // histogram generation
  std::vector<unsigned int> histogram(maxPixelValue + 1, 0);
  for (size_t i = 0; i < image.get_width(); ++i)
    for (size_t j = 0; j < image.get_height(); ++j)
      ++histogram[image.get_pixel(i,j)];

  // computation of the probabilities of each density level
  std::vector<double> prob(maxPixelValue + 1);
  for (size_t i = 0; i <= maxPixelValue; ++i) {
    prob[i] = static_cast<double>(histogram[i]) / numPixels;
  }

  // omega & mu computation
  std::vector<double> omega(maxPixelValue + 1);
  std::vector<double> mu(maxPixelValue + 1);
  omega[0] = prob[0];
  mu[0] = 0.0;
  for (size_t i = 1; i <= maxPixelValue; ++i) {
    omega[i] = omega[i-1] + prob[i];
    mu[i] = mu[i-1] + i * prob[i];
  }

  // sigma maximization
  // sigma stands for inter-class variance
  // and determines optimal threshold value
  std::vector<double> sigma(maxPixelValue + 1);
  size_t threshold = 0;
  double max_sigma = 0.0;
  for (size_t i = 0; i <= maxPixelValue-1; ++i) {
    if (omega[i] != 0.0 && omega[i] != 1.0)
      sigma[i] = square(mu[maxPixelValue] * omega[i] - mu[i])
          / (omega[i] * (1.0 - omega[i]));
    else
      sigma[i] = 0.0;
    if (sigma[i] > max_sigma) {
      max_sigma = sigma[i];
      threshold = i;
    }
  }

  // binarization
  for (size_t i = 0; i < image.get_width(); ++i)
    for (size_t j = 0; j < image.get_height(); ++j)
      if (image.get_pixel(i,j) > threshold)
        image.set_pixel(i,j, std::numeric_limits<png::gray_pixel>::max());
      else
        image.set_pixel(i,j, 0);
}
Exemple #2
0
void SGMStereo::convertToGrayscale(const png::image<png::rgb_pixel>& leftImage,
								   const png::image<png::rgb_pixel>& rightImage,
								   unsigned char* leftGrayscaleImage,
								   unsigned char* rightGrayscaleImage) const
{
	for (int y = 0; y < height_; ++y) {
		for (int x = 0; x < width_; ++x) {
			png::rgb_pixel pix = leftImage.get_pixel(x, y);
			leftGrayscaleImage[width_*y + x] = static_cast<unsigned char>(0.299*pix.red + 0.587*pix.green + 0.114*pix.blue + 0.5);
			pix = rightImage.get_pixel(x, y);
			rightGrayscaleImage[width_*y + x] = static_cast<unsigned char>(0.299*pix.red + 0.587*pix.green + 0.114*pix.blue + 0.5);
		}
	}
}
void dig_riverbed(int i, int j, png::gray_pixel_16 depth, png::image<png::gray_pixel_16>& topomap) {
	png::gray_pixel_16 cur_val,new_val,brush_depth;
	int brush_radius=2;
	int width = topomap.get_width();
	int height = topomap.get_height();
	for (int i_=i-brush_radius; i_<=i+brush_radius; i_++) {
		for(int j_=j-brush_radius; j_<=j+brush_radius; j_++) {
			if (i_<0||i_>width||j_<0||j_>=height) continue;
			double i_dist=i_-i;
			double j_dist=j_-j;
			double dist=sqrt(i_dist*i_dist+j_dist*j_dist);
			if(dist>brush_radius) continue;
			//double brush_depth_dbl = depth - depth*sin(dist/brush_radius*M_PI/2);
			double brush_depth_dbl = depth*cos(dist/brush_radius*M_PI/2);
			if(brush_depth_dbl < 0) brush_depth_dbl = 0;
			brush_depth = brush_depth_dbl;
			cur_val = topomap.get_pixel(i_,j_); 
			if(brush_depth >= cur_val) new_val = 0;
			else
				new_val = cur_val - brush_depth;
			if (new_val < cur_val)
				topomap.set_pixel(i_,j_,new_val);
		}
	}
}
Exemple #4
0
void binaryImageToNegative(png::image<png::gray_pixel> & image)
{
  for (size_t i = 0; i < image.get_width(); ++i)
    for (size_t j = 0; j < image.get_height(); ++j) {
      image.set_pixel(i,j, (image.get_pixel(i,j) == 0 ?
                              std::numeric_limits<png::gray_pixel>::max() : 0));
    }
}
void makeSegmentBoundaryImage(const png::image<png::rgb_pixel>& inputImage,
							  const png::image<png::gray_pixel_16>& segmentImage,
							  std::vector< std::vector<int> >& boundaryLabels,
							  png::image<png::rgb_pixel>& segmentBoundaryImage)
{
	int width = static_cast<int>(inputImage.get_width());
	int height = static_cast<int>(inputImage.get_height());
	int boundaryTotal = static_cast<int>(boundaryLabels.size());

	segmentBoundaryImage.resize(width, height);
	for (int y = 0; y < height; ++y) {
		for (int x = 0; x < width; ++x) {
			segmentBoundaryImage.set_pixel(x, y, inputImage.get_pixel(x, y));
		}
	}

	int boundaryWidth = 2;
	for (int y = 0; y < height - 1; ++y) {
		for (int x = 0; x < width - 1; ++x) {
			int pixelLabelIndex = segmentImage.get_pixel(x, y);

			if (segmentImage.get_pixel(x + 1, y) != pixelLabelIndex) {
				for (int w = 0; w < boundaryWidth - 1; ++w) {
					if (x - w >= 0) segmentBoundaryImage.set_pixel(x - w, y, png::rgb_pixel(128, 128, 128));
				}
				for (int w = 1; w < boundaryWidth; ++w) {
					if (x + w < width) segmentBoundaryImage.set_pixel(x + w, y, png::rgb_pixel(128, 128, 128));
				}
			}
			if (segmentImage.get_pixel(x, y + 1) != pixelLabelIndex) {
				for (int w = 0; w < boundaryWidth - 1; ++w) {
					if (y - w >= 0) segmentBoundaryImage.set_pixel(x, y - w, png::rgb_pixel(128, 128, 128));
				}
				for (int w = 1; w < boundaryWidth; ++w) {
					if (y + w < height) segmentBoundaryImage.set_pixel(x, y + w, png::rgb_pixel(128, 128, 128));
				}
			}
		}
	}

	boundaryWidth = 7;
	for (int y = 0; y < height - 1; ++y) {
		for (int x = 0; x < width - 1; ++x) {
			int pixelLabelIndex = segmentImage.get_pixel(x, y);

			if (segmentImage.get_pixel(x + 1, y) != pixelLabelIndex) {
				png::rgb_pixel negativeSideColor, positiveSideColor;
				int pixelBoundaryIndex = -1;
				for (int boundaryIndex = 0; boundaryIndex < boundaryTotal; ++boundaryIndex) {
					if ((boundaryLabels[boundaryIndex][0] == pixelLabelIndex && boundaryLabels[boundaryIndex][1] == segmentImage.get_pixel(x + 1, y))
						|| (boundaryLabels[boundaryIndex][0] == segmentImage.get_pixel(x + 1, y) && boundaryLabels[boundaryIndex][1] == pixelLabelIndex))
					{
						pixelBoundaryIndex = boundaryIndex;
						break;
					}
				}
				if (boundaryLabels[pixelBoundaryIndex][2] == 3) continue;
				else if (boundaryLabels[pixelBoundaryIndex][2] == 2) {
					negativeSideColor.red = 0;  negativeSideColor.green = 225;  negativeSideColor.blue = 0;
					positiveSideColor.red = 0;  positiveSideColor.green = 225;  positiveSideColor.blue = 0;
				} else if (pixelLabelIndex == boundaryLabels[pixelBoundaryIndex][boundaryLabels[pixelBoundaryIndex][2]]) {
					negativeSideColor.red = 225;  negativeSideColor.green = 0;  negativeSideColor.blue = 0;
					positiveSideColor.red = 0;  positiveSideColor.green = 0;  positiveSideColor.blue = 225;
				} else {
					negativeSideColor.red = 0;  negativeSideColor.green = 0;  negativeSideColor.blue = 225;
					positiveSideColor.red = 225;  positiveSideColor.green = 0;  positiveSideColor.blue = 0;
				}

				for (int w = 0; w < boundaryWidth - 1; ++w) {
					if (x - w >= 0) segmentBoundaryImage.set_pixel(x - w, y, negativeSideColor);
				}
				for (int w = 1; w < boundaryWidth; ++w) {
					if (x + w < width) segmentBoundaryImage.set_pixel(x + w, y, positiveSideColor);
				}
			}
			if (segmentImage.get_pixel(x, y + 1) != pixelLabelIndex) {
				png::rgb_pixel negativeSideColor, positiveSideColor;
				int pixelBoundaryIndex = -1;
				for (int boundaryIndex = 0; boundaryIndex < boundaryTotal; ++boundaryIndex) {
					if ((boundaryLabels[boundaryIndex][0] == pixelLabelIndex && boundaryLabels[boundaryIndex][1] == segmentImage.get_pixel(x, y + 1))
						|| (boundaryLabels[boundaryIndex][0] == segmentImage.get_pixel(x, y + 1) && boundaryLabels[boundaryIndex][1] == pixelLabelIndex))
					{
						pixelBoundaryIndex = boundaryIndex;
						break;
					}
				}
				if (boundaryLabels[pixelBoundaryIndex][2] == 3) continue;
				else if (boundaryLabels[pixelBoundaryIndex][2] == 2) {
					negativeSideColor.red = 0;  negativeSideColor.green = 225;  negativeSideColor.blue = 0;
					positiveSideColor.red = 0;  positiveSideColor.green = 225;  positiveSideColor.blue = 0;
				} else if (pixelLabelIndex == boundaryLabels[pixelBoundaryIndex][boundaryLabels[pixelBoundaryIndex][2]]) {
					negativeSideColor.red = 225;  negativeSideColor.green = 0;  negativeSideColor.blue = 0;
					positiveSideColor.red = 0;  positiveSideColor.green = 0;  positiveSideColor.blue = 225;
				} else {
					negativeSideColor.red = 0;  negativeSideColor.green = 0;  negativeSideColor.blue = 225;
					positiveSideColor.red = 225;  positiveSideColor.green = 0;  positiveSideColor.blue = 0;
				}

				for (int w = 0; w < boundaryWidth - 1; ++w) {
					if (y - w >= 0) segmentBoundaryImage.set_pixel(x, y - w, negativeSideColor);
				}
				for (int w = 1; w < boundaryWidth; ++w) {
					if (y+ w < height) segmentBoundaryImage.set_pixel(x, y + w, positiveSideColor);
				}
			}
		}
	}
}
Exemple #6
0
Eigen::Vector3f bumpier::model::position(const png::image<png::gray_pixel_16>& image, int x, int y) const
{
    return position(Eigen::Vector2f((float)x / image.get_width(), (float)y / image.get_height()), (float)image.get_pixel(x, y) / 0xFFFF);
}