I try to make an image binary but it doesn't work

i’m trying to make an image binary but whenever I try it “dissappears”, i’ve been using it several times and this have never happened before


Allow me this remark:
Tips for posting your first question : Please post a representative, original image file, as well as a brief explanation (avoiding science-specific “jargon” ) and/or an annotated version of the image to better indicate what solution you are after.

Add the part of your program that does not work.
You will more easily have advice.
Have a good day.