void ComputeHarrisFeatures(CFloatImage &image, FeatureSet &features)
{
//Create grayscale image used for Harris detection
CFloatImage grayImage=ConvertToGray(image);
//Create image to store Harris values
CFloatImage harrisImage(image.Shape().width,image.Shape().height,1);
//Create image to store local maximum harris values as 1, other pixels 0
CByteImage harrisMaxImage(image.Shape().width,image.Shape().height,1);
//compute Harris values puts harris values at each pixel position in harrisImage.
//You'll need to implement this function.
computeHarrisValues(grayImage, harrisImage);
// Threshold the harris image and compute local maxima. You'll need to implement this function.
computeLocalMaxima(harrisImage,harrisMaxImage);
// Prints out the harris image for debugging purposes
CByteImage tmp(harrisImage.Shape());
convertToByteImage(harrisImage, tmp);
WriteFile(tmp, "harris.tga");
// TO DO--------------------------------------------------------------------
//Loop through feature points in harrisMaxImage and fill in information needed for
//descriptor computation for each point above a threshold. We fill in id, type,
//x, y, and angle.
CFloatImage A(grayImage.Shape());
CFloatImage B(grayImage.Shape());
CFloatImage C(grayImage.Shape());
CFloatImage partialX(grayImage.Shape());
CFloatImage partialY(grayImage.Shape());
GetHarrisComponents(grayImage, A, B, C, &partialX, &partialY);
int featureCount = 0;
for (int y=0;y<harrisMaxImage.Shape().height;y++) {
for (int x=0;x<harrisMaxImage.Shape().width;x++) {
// Skip over non-maxima
if (harrisMaxImage.Pixel(x, y, 0) == 0)
continue;
//TO DO---------------------------------------------------------------------
// Fill in feature with descriptor data here.
Feature f;
f.type = 2;
f.id = featureCount++;
f.x = x;
f.y = y;
f.angleRadians = GetCanonicalOrientation(x, y, A, B, C, partialX, partialY);
//atan(partialY.Pixel(x, y, 0)/partialX.Pixel(x, y, 0));
// Add the feature to the list of features
features.push_back(f);
}
}
}
// Compute features using Harris corner detection method
void ComputeHarrisFeatures(CFloatImage &image, FeatureSet &features)
{
// Create grayscale image used for Harris detection
CFloatImage grayImage = ConvertToGray(image);
// Create image to store Harris values
CFloatImage harrisImage(image.Shape().width,image.Shape().height,1);
// Create image to store local maximum harris values as 1, other pixels 0
CByteImage harrisMaxImage(image.Shape().width,image.Shape().height,1);
// Create image to store orientation values
CFloatImage orientationImage(image.Shape().width, image.Shape().height, 1);
// Compute the harris score at each pixel position, storing the result in in harrisImage.
computeHarrisValues(grayImage, harrisImage, orientationImage);
// Threshold the harris image and compute local maxima.
computeLocalMaxima(harrisImage,harrisMaxImage);
// Save images
CByteImage tmp(harrisImage.Shape());
CByteImage tmp2(harrisImage.Shape());
convertToByteImage(harrisImage, tmp);
convertToByteImage(grayImage, tmp2);
WriteFile(tmp2, "grayImg.tga");
WriteFile(tmp, "harris.tga");
WriteFile(harrisMaxImage, "harrisMax.tga");
// Loop through feature points in harrisMaxImage and fill in id, type, x, y, and angle
// information needed for descriptor computation for each feature point, then add them
// to feature set
int id = 0;
for (int y=0; y < harrisMaxImage.Shape().height; y++) {
for (int x=0; x < harrisMaxImage.Shape().width; x++) {
if (harrisMaxImage.Pixel(x, y, 0) == 1) {
Feature f;
f.id = id;
f.type = 2;
f.x = x;
f.y = y;
f.angleRadians = orientationImage.Pixel(x,y,0);
features.push_back(f);
id++;
}
}
}
}
