Pencil is hard to pick up on any optical scanner or copier. I do not have access to my HP All-In-One at the moment, so I do not know if there is a clear solution for your issue within software.
You may try opening the Printer Software to see if there are settings to darken the scan, or the easy way is to darken in copy mode and make a darker copy and then scan the copy in?? You may need to copy the copy as well??
In the future, use something other than pencil. Felt tip pens are better than ball point. Black ink is better than blue. Also, if you must use pencil, try a #3 pencil which is softer than #2 and should be somewhat darker.
Hope this helps.
JamesO
You may try opening the Printer Software to see if there are settings to darken the scan, or the easy way is to darken in copy mode and make a darker copy and then scan the copy in?? You may need to copy the copy as well??
In the future, use something other than pencil. Felt tip pens are better than ball point. Black ink is better than blue. Also, if you must use pencil, try a #3 pencil which is softer than #2 and should be somewhat darker.
Hope this helps.
JamesO