bsfm::DescriptorExtractor Class Reference

#include <descriptor_extractor.h>

Public Member Functions
	DescriptorExtractor ()
	~DescriptorExtractor ()
bool	SetDescriptor (const std::string &descriptor_type)
bool	DescribeFeatures (const Image &image, KeypointList &keypoints, std::vector< Feature > &features_out, std::vector< Descriptor > &descriptors_out)

Private Attributes
std::string	descriptor_type_
cv::Ptr< cv::DescriptorExtractor >	extractor_

Detailed Description

Definition at line 56 of file descriptor_extractor.h.

Constructor & Destructor Documentation

bsfm::DescriptorExtractor::DescriptorExtractor ( )

inline

Definition at line 59 of file descriptor_extractor.h.

{ }

bsfm::DescriptorExtractor::~DescriptorExtractor ( )

inline

Definition at line 60 of file descriptor_extractor.h.

{ }

Member Function Documentation

bool bsfm::DescriptorExtractor::DescribeFeatures	(	const Image &	image,
		KeypointList &	keypoints,
		std::vector< Feature > &	features_out,
		std::vector< Descriptor > &	descriptors_out
	)

Definition at line 71 of file descriptor_extractor.cpp.

                                            {
  // Make the user has called SetDescriptor().
  if (descriptor_type_.empty()) {
    VLOG(1)
        << "Descriptor has not been specified via SetDescriptor(). Failed to "
           "extract descriptors.";
    return false;
  }

  CHECK(extractor_) << "The descriptor extractor is null.";
  features_out.clear();

  // Convert the input image to OpenCV's format. Note that descriptors must be
  // extracted on the grayscale image, and that the image format must be CV_8U.
  cv::Mat cv_image;
  image.ToCV(cv_image);
  cv_image.convertTo(cv_image, CV_8U, 255);

  // Extract descriptors from the provided keypoints in the image.
  cv::Mat cv_descriptors;
  try {
    extractor_->compute(cv_image, keypoints, cv_descriptors);
  } catch (const std::exception& e) {
    VLOG(1) << "Failed to extract descriptors: " << e.what();
    return false;
  }

  // Convert the computed OpenCV-type descriptors and keypoints into a list of
  // features and descriptors.
  for (size_t ii = 0; ii < keypoints.size(); ++ii) {
    Feature feature;
    feature.u_ = keypoints[ii].pt.x;
    feature.v_ = keypoints[ii].pt.y;
    features_out.push_back(feature);

    MatrixXd descriptor_mat;
    OpenCVToEigenMat<double>(cv_descriptors.row(ii), descriptor_mat);

    // Need to explicitly convert from matrix to vector.
    Descriptor descriptor = descriptor_mat.row(0).transpose();
    descriptors_out.push_back(descriptor);
  }

  return true;
}

bool bsfm::DescriptorExtractor::SetDescriptor

(

const std::string &

descriptor_type

)

Definition at line 42 of file descriptor_extractor.cpp.

                                                                        {
  // Set the descriptor type.
  descriptor_type_ = descriptor_type;
  bool valid_descriptor_type = true;

  // Create an OpenCV descriptor extractor.
  if (descriptor_type.compare("SIFT") == 0) {
    extractor_ = cv::DescriptorExtractor::create("SIFT");
  } else if (descriptor_type_.compare("SURF") == 0) {
    extractor_ = cv::DescriptorExtractor::create("SURF");
  } else if (descriptor_type_.compare("BRIEF") == 0) {
    extractor_ = cv::DescriptorExtractor::create("BRIEF");
  } else if (descriptor_type_.compare("BRISK") == 0) {
    extractor_ = cv::DescriptorExtractor::create("BRISK");
  } else if (descriptor_type_.compare("FREAK") == 0) {
    extractor_ = cv::DescriptorExtractor::create("FREAK");
  } else if (descriptor_type_.compare("ORB") == 0) {
    extractor_ = cv::DescriptorExtractor::create("ORB");
  } else {
    VLOG(1) << "Descriptor type \"" << descriptor_type
            << "\"is not available. Defaulting to SIFT.";
    extractor_ = cv::DescriptorExtractor::create("SIFT");
    valid_descriptor_type = false;
    descriptor_type_ = "SIFT";
  }

  return valid_descriptor_type;
}

Member Data Documentation

std::string bsfm::DescriptorExtractor::descriptor_type_

private

Definition at line 74 of file descriptor_extractor.h.

cv::Ptr<cv::DescriptorExtractor> bsfm::DescriptorExtractor::extractor_

private

Definition at line 75 of file descriptor_extractor.h.

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The documentation for this class was generated from the following files:

• /Users/eanelson/Git/berkeley_sfm/src/cpp/matching/descriptor_extractor.h
• /Users/eanelson/Git/berkeley_sfm/src/cpp/matching/descriptor_extractor.cpp