📝 dinglehopper: Document REPORT_PREFIX (Closes GH-27.)

README.md

@@ -36,6 +36,9 @@ Usage: dinglehopper [OPTIONS] GT OCR [REPORT_PREFIX]
   In that case, use --no-metrics to disable the then meaningless metrics and
   also change the color scheme from green/red to blue.
 
+  The comparison report will be written to $REPORT_PREFIX.{html,json}, where
+  $REPORT_PREFIX defaults to "report".
+
 Options:
   --metrics / --no-metrics  Enable/disable metrics and green/red
   --help                    Show this message and exit.

qurator/dinglehopper/cli.py

@@ -109,6 +109,9 @@ def main(gt, ocr, report_prefix, metrics):
     an OCR software, but you may use dinglehopper to compare two OCR results. In
     that case, use --no-metrics to disable the then meaningless metrics and also
     change the color scheme from green/red to blue.
+
+    The comparison report will be written to $REPORT_PREFIX.{html,json}, where
+    $REPORT_PREFIX defaults to "report".
     """
     process(gt, ocr, report_prefix, metrics=metrics)