Auto-Multiple-Choice-Marking.md

@@ -20,6 +20,12 @@
 
 ![pdf_extraction](uploads/7a502f99eeada1db4c0996f3cb831606/pdf_extraction.png)
 
+7. After the command completed [a new line in terminal will appear with a flashing cursor after $], run the command
+
+    `find . -maxdepth 1 -type f -iname '*.jpg' -exec magick {} -colorspace Gray -level 35%,95% {} \;`
+
+    This will convert all JPEG images to grayscale, map the darkest 35% of pixels to black and the brightest 5% to white. (The answer recognition will run with less uncertainty for images with higher contrast).
+
 ## 2. Data capture with the Auto Multiple Choice software
 
 1. Start the Automultiple-Choice-Software installed on tango or on any physical D-MATH Linux client. Then, open the project.