feature key SIFT_v0.2
The feature-key-SIFT software provides a front-end to the SIFT implementation offered by the OpenCV library. Taking an image as input, it generates a list of keypoints that are the exported in an output file.
Grayscale images are expected by the software. If color images are given as input, the OpenCV image reader convert it automatically into grayscale images.
The feature-key-SIFT software expect the following parameters. Starting with the stream parameters :
--input -i
Path of the input image.
--output -o
Path of the output keypoints file.
OpenCV SIFT implementation parameters :
--maximum -m (OpenCV : nfeatures)
--octave -a (OpenCV : nOctaveLayers)
--contrast -c (OpenCV : contrastThreshold)
--edge -e (OpenCV : edgeThreshold)
--sigma -s (OpenCV : sigma)
OpenCV SIFT parameters. Please see OpenCV documentation for more
information.
Prefiltering parameters :
--edge-x -x, --edge-y -y
Size, in pixels, of the image edges. Keypoints that are detected
outside of those edges are not exported in the output file.
Considering the following image taken with an Eyesis4Pi camera in Geneva :
and the standard OpenCV SIFT parameters, the following keypoints are generated after grayscale conversion :
Changing the value of the Gaussian parameter, the number of generated keypoint can be augmented or reduced :
The two last images are generated using the feature-key-view software.
The software binary can be build using its specific makefile by simply typing in its base directory :
$ make clean && make build [OPENMP=false]
The binary is placed in the local bin directory and is not copied in the main bin directory. To generate the documentation, use the command :
$ make clean-documentation && make documentation
To install or uninstall the binaries on the local computer, use the commands :
# make install
# make uninstall