shs - Sample Hough Space. A tool to sample the Motion Hough Space. The sampled data can be used to visualize the shape of the Hough Space, using any package to display 3D data (for example xprism). The program also returns the position of the global minimum and estimate confidence matrix.

NAME

shs

SYNOPSIS

shs -s image_sequence_name -x x_coordinate_of_ROI -y y_coordinate_of_ROI -h horizontal_size_of_ROI -v vertical_size_of_ROI [ -r resolution_in_the_HS ] [ -f passes_of_binomial_filter ] [ -m motion_threshold ] [ -k kernel_type ] [ -a vx_min_value ] [ -A vx_max_value ] [ -b vy_min_value ] [ -B vy_max_value ] [ -o output_filename ] [ -i interactive_flag ] [ -U print_usage ]

DESCRIPTION

The shs program samples the Hough Space (HS) for a given sequence (two frames saved in .seq format) and saves results in text files. The HS is sampled with the pre-specified resolution, and for motion parameters values from the specified intervals. The two parameter motion model is used. A set of kernels is available, including: Absolute, Quadratic, Hampel_1_2_1, Huber min-max, Tukey. The optimal kernel depends on the type of sequence and noise level and distribution.

OPTIONS

-s image_sequence_name
Specifies the file name of the sequence (stored in the sequence [.seq] format).
-f number_of_passes_of_binomial_filter (default 3)
Defines the number of passes of the binomial filter used to low-pass filter the sequence.
-m motion_threshold (default 0)
Defines the threshold on the Frame Difference. Pixels for which the Frame Difference is less then the threshold do not contribute to the Hough Space
-x x_coord
x coordinate of the top right corner of the Region of Interest (ROI)
-y y_coord
y coordinate of the top right corner of the ROI
-h horizontal_size
horizontal size of the Region of Interest
-v vertical_size
vertical size of the Region of Interest
-r resolution_in_the_HS (default 1 pel)
Specifies the resolution in the Hough (Motion Parameter) Space
-k kernel_type (default 0)
Specifies the kernel type: 0 - Absolute 1 - Quadratic 2 - Huber min-max 3 - Hampel 1-2-1 4 - Tukey 5 - Normalized Correlation
-a vx_min -A vx_max (default [-8,8])
-b vy_min -B vy_max (default [-8,8])
-o output_filename (default hough)
Write samples of the Hough Space into a text files. Three file are created: hough_space.dat - total support for motion parameters from the ROI hough_mean.dat - mean value of support form the region ROI hough_std.dat - standard deviation of support within the ROI
-U
Prints usage

SELECTING RUN PARAMETERS

EXAMPLE RUN

Example 1 (running for the command line) shs -s is4.seq -x20 -y20 -h32 -v32 -f 3 -r 0.1 -a -7.0 -A -3.0 -b -2.0 -B 2.0 -o is4_hough Sample Hough Space for sequence <is4.seq>. Low-pass filter reference and consecutive frames using Binomial filter (3 passes). Sample Hough Space for Region of Interest with upper right corner at pixel (20,20) and horizontal and vertical size of 32 pixels. Region of interest in the Hough Space is defined as [-7.0, -3.0] for Vx and [-2.0, 2.0] for Vy. Resolution in the Parameter space is 0.1 pel. Save results to files with steam is4_hough (is4_hough_space.dat, is4_hough_mean.dat, is4_hough_std.dat are created). Example 2 (interactive use) shs -i Interactive run. Program prompts the user for the values of run parameters.

SEE ALSO

RHflow2D, RHflow4D, RHglob2D, RHglob4Dr. For the definition of the Hough Space see:

[1] M. Bober and J. Kittler, Robust motion analysis, CVPR1994, pp 947--952, IEEE Computer Society Press.

[2] M. Bober and J. Kittler, Estimation of general multimodal motion: an approach based on robust statistics and Hough transform, Image and Vision Computing, Volume 12, Number 12, 1994, pp 661--668

BUGS

During sampling procedure, the block displacement is not checked against valid block positions. If displacement range move block out of the image a segmentation error may result.

COPYRIGHT

This program is copyrighted, see the Copy-Right Notice.

AUTHOR

Miroslaw Bober, Vision Speech and Signal Processing Group, University of Surrey, Guildford, Surrey, GU2 5XH, United Kingdom. M.Bober@ee.surrey.ac.uk
03-Feb-98. Automatically converted by man2html, written by G.Matas (g.matas@ee.surrey.ac.uk)