auto-multiple-choice-analyse — automatic data capture from scans for AMC multiple choice exams.
auto-multiple-choice analyse --projet
project-dir [--seuil-coche threshold] [--tol-marque tol] [ --list-fichiers
files-list.txt | scan-files... ]
The auto-multiple-choice analyse command performs automatic
data capture from scans of completed answer sheets of an AMC multiple
choice questionnaire. Before calling
auto-multiple-choice analyse, auto-multiple-choice-prepare(1) should have been called to make working documents
(--mode s) and the layout should have been processed
with auto-multiple-choice-meptex(1).
--data
data-dirgives the directory where data files are (see for example
auto-multiple-choice-meptex(1)). Defaults to
project-dir/data
--cr
project-cr-dirgives a directory where to create image reports of the
data capture (zooms on the boxes in a zooms
sub-directory, name filed extraction as a
name-*.jpg file, and layout report as a
page-*.jpg file).
--projet
project-dirWhen using this option, if --cr is not
used, project-cr-dir will be set to
project-dir/cr
Giving the names of the scan files to process can be done in two ways:
these names can be given as arguments,
these names can be written to a plain file (one filename per
line), using the --list-fichiers
to give the
name of this file.files-list.txt
Some parameters for data capture may be set using the following options:
--prop
proportionsets the proportion of each box that will be measured to decide if the box is ticked or not. Default value is 0.8.
--bw-threshold
thresholdThis parameter is used when converting the grayscale scan file to black and white. To get more black pixels, use a greater value. To get more white pixels, use a smaller value. The threshold must be between 0 and 1. The default value is 0.6.
--ignore-redWith this option, only red channel will be used from color scans. This way, all that is written in red will be ignored in the scan. This can be useful when the boxes are printed in red.
--tol-marque
toldefines the tolerance when detecting the four marks in the
scans corners. These marks are detected looking for black
connected components which dimensions are
closed to the target dimension
target (exact dimensions of the marks
if printing/scanning process where perfectly accurate). If
tol is a real number, accepted
dimensions are those between
(1-tol)*target
and
(1+tol)*target.
If tol is
"tinf,tsup"
(where tinf and
tsup are real numbers), accepted
dimensions are those between
(1-tinf)*target
and
(1+tsup)*target.
A standard value is 0.2.
--multipleThis option is to be used when the scans are photocopies from some subjects (different students can have the same subject). In this case, copy numbers are allocated to students so that their answer sheets, with the same subject number, can be differentiated.
--pre-allocate
copy_idThis option can be used in conjunction with
--multiple. The copy numbers used for the scans
will start from copy_id, in the same
order than the scans given as arguments.
Use one of these options to tell if you allow processing of scans where only three corner marks are present.
--debug
file.loggives a file to fill with debugging information.