CITlabErrorRate

A tool for computing error rates for different algorithms:

Requirements

• Java >= version 8
• Maven
• All further dependencies are gathered via Maven

Build

git clone https://github.com/CITlabRostock/CITlabErrorRate
cd CITlabErrorRate
mvn package [-DskipTests=true]

Running:

End-2-End Character Error Rate (CER)

This tool makes it possible to measure the CER or WER of an End2End system. In general it calculate the number of manipulations (insertion, deletion, substitution) that have to be done to come from the hypothesis/recognition to the ground truth/reference. The CER/WER is equal to #manipulation/#GT, whereals #GT is the number of ground truth characters/words.

The tool has several options to be configured. A first overview over all parameters can be gathered by

java -jar target/CITlabErrorRate-jar-with-dependencies.jar \
<list_pageXml_groundtruth> \
<list_pageXml_hypothesis> \
[-d] [-D] [-g] [-h] [-l] [-N] [-n] [-r] [-s] [-t <arg>] [-u]

Parameters that manipulate/normalize both, the ground truth and the hypothesis:

• -l The CER is only calculated on letters, numbers and spaces. All other characters like punktuations and symbols are ignored. Examples: this, 1 word! leads to this 1 word ; 31.Nov.2019 leads to 31Nov2019; 12.000 $ budget->12000 budget
• -N the text will be normalized according the unicode standard NFKC (see http://unicode.org/reports/tr15/ for details). Example: ſ leads to s
• -n the text will be normalized according the unicode standard NFC (see http://unicode.org/reports/tr15/ for details). Example: a^ leads to â, whereas ^ is the accent circumfelx\u+005e
• -u make text to upper (so it is case insensitive). Example: Straße leads to STRASSE

Parameter that determin how the error is calculated:

• -r the reading order is ignored. So ["first line", "second line"] vs. ["second line", "first line"] would be correct.
• -s the right segmentation plays a role. That means a space \+u0020 can be interpretet as space or as split of lines. So ["split and", "merge lines"] vs. ["split", "and merge", "lines"] would be correct.
• -g the geometric postion of the line plays a role. The couverage between two lines have above a threshold (see parameter -t).
• -t <FLOAT> the minimal couverage [0.0,1.0) between two baselines so that they were assumed to be adjacent. The Method with Intesection-over-Union is not implemented so far.

HTR:

It can calculate Character Error Rate (CER), Word Error Rate (WER), Bag of Tokens (BOG) and some more metrics. Type

java -cp target/CITlabErrorRate.jar de.uros.citlab.errorrate.HtrError --help

for more information concerning evaluating an HTR result if the files are PAGE-XML-files. For raw UTF-8 encoded textfiles use

java -cp target/CITlabErrorRate.jar de.uros.citlab.errorrate.HtrErrorTxt --help

or

java -cp target/CITlabErrorRate.jar de.uros.citlab.errorrate.HtrErrorTxtLeip

KWS:

To calculate measures for KWS

java -cp target/CITlabErrorRate.jar de.uros.citlab.errorrate.KwsError

can be used. Use --help to see the configuration opportunities

Text2Image

To calculate measures for image alignment

java -cp target/CITlabErrorRate.jar de.uros.citlab.errorrate.Text2ImageError

can be used. Use --help to see the configuration opportunities