[Petra-Kathi]

Adjust score images in the Gimp

The for-free image manipulation programm Gimp is available on both Linux and Windows, and presumably MacOS as well.
(beware: I used the German version of the Gimp, so the english naming of the menu items may not be correct, as I translated them on the fly.)

# load image in Gimp

to rotate by a few degrees:
# select by menu: tools => transformations => rotate
# rotate visually until image seems right. (Aligning with the borders of an overlapping other window may help.)

to deskew:
# select by menu: tools => transformations => perspective
# adjust visually by shoving the four corners until image seems right.

to enhance contrast/brightness:
# select by menu: colours => curves
# grab black and white points for the value histogram, and shove them both more to the center, to discriminate better between (black) score details and (white) background. To get a clearer picture where the original image's majority values for those domains lie, better change histogram to a logarithmic representation.


Have fun!

Petra