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.IX Title "MRGINGHAM 1"
.TH MRGINGHAM 1 2024-03-24 "mrgingham 1.24" "mrgingham: chessboard corner finder"
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.SH NAME
mrgingham\-observe\-pixel\-uncertainty \- Evaluate observed point distribution from stationary observations
.SH SYNOPSIS
.IX Header "SYNOPSIS"
.Vb 3
\&  $ observe\-pixel\-uncertainty \*(Aq*.png\*(Aq
\&    Evaluated 49 observations
\&    mean 1\-sigma for independent x,y: 0.26
\&
\&  $ mrcal\-calibrate\-cameras \-\-observed\-pixel\-uncertainty 0.26 .....
\&  [ mrcal computes a camera calibration ]
.Ve
.SH DESCRIPTION
.IX Header "DESCRIPTION"
mrgingham has finite precision, so repeated observations of the same board will
produce slightly different corner coordinates. This tool takes in a set of
images (assumed observing a chessboard, with both the camera and board
stationary). It then outputs the 1\-standard\-deviation statistic for the
distribution of detected corners. This can then be passed in to mrcal:
\&'mrcal\-calibrate\-cameras \-\-observed\-pixel\-uncertainty ...'
.PP
The distribution of the detected corners is assumed to be gaussian, and
INDEPENDENT in the horizontal and vertical directions. If the x and y
distributions are each s, then the LENGTH of the deviation of each pixel is a
Rayleigh distribution with expected value s*sqrt(pi/2) ~ s*1.25
.PP
THIS TOOL PERFORMS VERY LIGHT OUTLIER REJECTION; IT IS ASSUMED THAT THE SCENE IS
STATIONARY
.SH OPTIONS
.IX Header "OPTIONS"
.SS "POSITIONAL ARGUMENTS"
.IX Subsection "POSITIONAL ARGUMENTS"
.Vb 8
\&  input                 Either 1: A glob that matches images observing a
\&                        stationary calibration target. This must be a GLOB. So
\&                        in the shell pass in \*(Aq*.png\*(Aq and NOT *.png. These are
\&                        processed by \*(Aqmrgingham\*(Aq and the arguments passed in
\&                        with \-\-mrgingham. Or 2: a vnlog representing corner
\&                        detections from these images. This is assumed to be a
\&                        file with a filename ending in .vnl, formatted like
\&                        \*(Aqmrgingham\*(Aq output: 3 columns: filename,x,y
.Ve
.SS "OPTIONAL ARGUMENTS"
.IX Subsection "OPTIONAL ARGUMENTS"
.Vb 10
\&  \-h, \-\-help            show this help message and exit
\&  \-\-show {geometry,histograms}
\&                        Visualize something. Arguments can be: "geometry":
\&                        show the 1\-stdev ellipses of the distribution for each
\&                        chessboard corner separately. "histograms": show the
\&                        distribution of all the x\- and y\-deviations off the
\&                        mean
\&  \-\-mrgingham MRGINGHAM
\&                        If we\*(Aqre processing images, these are the arguments
\&                        given to mrgingham. If we are reading a pre\-computed
\&                        file, this does nothing
\&  \-\-num\-corners NUM_CORNERS
\&                        How many corners to expect in each image. If this is
\&                        wrong I will throw an error. Defaults to 100
\&  \-\-imagersize IMAGERSIZE IMAGERSIZE
\&                        Optional imager dimensions: width and height. This is
\&                        optional. If given, we use it to size the "\-\-show
\&                        geometry" plot
.Ve
.SH REPOSITORY
.IX Header "REPOSITORY"
<https://github.com/dkogan/mrgingham>
.SH AUTHOR
.IX Header "AUTHOR"
Dima Kogan, \f(CW\*(C`<dima@secretsauce.net>\*(C'\fR
.SH "LICENSE AND COPYRIGHT"
.IX Header "LICENSE AND COPYRIGHT"
This library is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free
Software Foundation; either version 2.1 of the License, or (at your option) any
later version.
.PP
Copyright 2017\-2018 California Institute of Technology
.PP
Copyright 2017\-2018 Dima Kogan (\f(CW\*(C`dima@secretsauce.net\*(C'\fR)