Name

AMC-analyse — automatic data capture from scans for AMC multiple choice exams.

Synopsis

auto-multiple-choice analyse --projet project-dir [--seuil-coche threshold] [--tol-marque tol] [ --list-fichiers files-list.txt | scan-files... ]

Description

The AMC-analyse.pl command performs automatic data capture from scans of completed answer sheets of an AMC multiple choice questionnaire. Before calling AMC_analyse.pl, AMC-prepare(1) should have been called to make working documents (--mode s) and then MEP files (--mode m).

--mep project-mep-dir

gives the directory where MEP files (prepared by AMC-prepare(1)) can be found.

--cr project-cr-dir

gives a directory where to create reports of the data capture.

--projet project-dir

When using this option, if --cr is not used, project-cr-dir will be set to project-dir/cr, and if --mep is not used, project-mep-dir will be set to project-dir/mep.

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 files-list.txt to give the name of this file.

Some parameters for data capture may be set using the following options:

--seuil-coche threshold

When deciding whether a box is checked or not, AMC-analyse.pl compares the black ratio (number of black pixels over total number of pixels) to threshold. If the black ratio is greater then threshold, the box is declared to be checked. Standard values can be 0.15 in the standard layout, or 0.5 for separate answer sheet layout (in this last case, letters are drawn in the boxes, and the students are told to fill the boxes entirely). The black ratio is written in the data capture reports, so that this threshold value can be refined later without calling AMC-analyse.pl again.

--tol-marque tol

defines 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 acurate). 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.

--debug file.log

gives a file to fill with debugging information.