.\" -*- mode: troff; coding: utf-8 -*- .\" Automatically generated by Pod::Man 5.01 (Pod::Simple 3.43) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" \*(C` and \*(C' are quotes in nroff, nothing in troff, for use with C<>. .ie n \{\ . ds C` "" . ds C' "" 'br\} .el\{\ . ds C` . ds C' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode transform. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" .\" If the F register is >0, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .nr rF 0 .if \n(.g .if rF .nr rF 1 .if (\n(rF:(\n(.g==0)) \{\ . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF .\" ======================================================================== .\" .IX Title "MRCAL 1" .TH MRCAL 1 2024-02-04 "mrcal 2.3-4.1~exp1" "mrcal: camera projection, calibration toolkit" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH NAME mrcal\-show\-projection\-uncertainty \- Visualize the expected projection error due to noise in calibration\-time input .SH SYNOPSIS .IX Header "SYNOPSIS" .Vb 3 \& $ mrcal\-show\-projection\-uncertainty left.cameramodel \& ... a plot pops up showing the projection uncertainty of the intrinsics in \& ... this model .Ve .SH DESCRIPTION .IX Header "DESCRIPTION" The operation of this tool is documented at .PP A calibration process produces the best-fitting camera parameters. To be able to use these parameters we must know how trustworthy they are. This tool examines the uncertainty of projection using a given camera model. The projection operation uses the intrinsics only, but the uncertainty must take into account the calibration-time extrinsics and the calibration-time observed object poses as well. This tool visualizes the expected value of projection error across the imager. Areas with a high expected projection error are unreliable, and observations in those regions cannot be used for further work (localization, mapping, etc). .PP There are several modes of operation: .PP \&\- By default we look at projection of points some distance away from the camera (given by \-\-distance). We evaluate the uncertainty of these projections everywhere across the imager, and display the results as a heatmap with overlaid contours .PP \&\- With \-\-vs\-distance\-at we evaluate the uncertainty along an observation ray mapping to a single pixel. We show the uncertainty vs distances from the camera along this ray .PP See for a full description of the computation performed here .SH OPTIONS .IX Header "OPTIONS" .SS "POSITIONAL ARGUMENTS" .IX Subsection "POSITIONAL ARGUMENTS" .Vb 2 \& model Input camera model. If "\-\*(Aq is given, we read standard \& input .Ve .SS "OPTIONAL ARGUMENTS" .IX Subsection "OPTIONAL ARGUMENTS" .Vb 10 \& \-h, \-\-help show this help message and exit \& \-\-vs\-distance\-at VS_DISTANCE_AT \& If given, we don\*(Aqt compute the uncertainty everywhere \& in the image at a constant distance from the camera, \& but instead we look at different distances at one \& pixel. This option takes a single argument: the "X,Y" \& pixel coordinate we care about, or "center" to look at \& the center of the imager or "centroid" to look at the \& center of the calibration\-time chessboards. This is \& exclusive with \-\-gridn and \-\-distance and \& \-\-observations and \-\-cbmax \& \-\-gridn GRIDN GRIDN How densely we should sample the imager. By default we \& use a 60x40 grid \& \-\-distance DISTANCE By default we display the projection uncertainty \& infinitely far away from the camera. If we want to \& look closer in, the desired observation distance can \& be given in this argument \& \-\-isotropic By default I display the expected value of the \& projection error in the worst possible direction of \& this error. If we want to plot the RMS of the worst \& and best directions, pass \-\-isotropic. If we assume \& the errors will apply evenly in all directions, then \& we can use this metric, which is potentially easier to \& compute \& \-\-observations If given, I display the pixel observations at \& calibration time. This should correspond to the low\- \& uncertainty regions. \& \-\-valid\-intrinsics\-region \& If given, I overlay the valid\-intrinsics region onto \& the plot \& \-\-cbmax CBMAX Maximum range of the colorbar \& \-\-title TITLE Title string for the plot. Overrides the default \& title. Exclusive with \-\-extratitle \& \-\-extratitle EXTRATITLE \& Additional string for the plot to append to the \& default title. Exclusive with \-\-title \& \-\-hardcopy HARDCOPY Write the output to disk, instead of an interactive \& plot \& \-\-terminal TERMINAL gnuplotlib terminal. The default is good almost \& always, so most people don\*(Aqt need this option \& \-\-set SET Extra \*(Aqset\*(Aq directives to gnuplotlib. Can be given \& multiple times \& \-\-unset UNSET Extra \*(Aqunset\*(Aq directives to gnuplotlib. Can be given \& multiple times .Ve .SH REPOSITORY .IX Header "REPOSITORY" .SH AUTHOR .IX Header "AUTHOR" Dima Kogan, \f(CW\*(C`\*(C'\fR .SH "LICENSE AND COPYRIGHT" .IX Header "LICENSE AND COPYRIGHT" Copyright (c) 2017\-2021 California Institute of Technology ("Caltech"). U.S. Government sponsorship acknowledged. All rights reserved. .PP Licensed under the Apache License, Version 2.0 (the "License"); You may obtain a copy of the License at .PP .Vb 1 \& http://www.apache.org/licenses/LICENSE\-2.0 .Ve