Histogram adjustment tutorial for graphite drawing

This tutorial shows how the histogram of a photograph of a black and white artwork can be adjusted to match closely the appearance of the original prior to its submission to DeviantArt, by using the free photo-editing program GIMP (Version 2.8.14).  Other photo-editing programs are likely to offer similar facilities for this correction.

This is one of a series of tutorials covering photographing a drawing, correction of barrel distortion, correction of perspective distortion and adjustment of the histogram of the photograph (in this tutorial ).

I have submitted three other tutorials in this series
                            Minimising Graphite Shine                           
                            Barrel Distortion Correction       
                            Perspective Distortion Correction 

These tutorials update my earlier  Tutorial in which I used a less versatile free photo-editing program and mentioned GIMP only in an update in the description below the tutorial.  I hope that these new ones will clarify the methods that I use.