Digital enhancement of lighted megalithic art (petroglyphs)

Some experiments are being done with different lighting directions of megalithic art (petroglyphs made by neolithic humans). This web-page will be build up during time when more experience is gained, so bear with me, give your feedback and come back in the future.

Cairn T

Some pictures were made of megalithic art on stone 14 in the neolithic cairn of Cairn T, while the direction of the light shining on the petroglyphs has been changed (I used battery powered video lamp; UNOMAT CAM20, 20W?):

These pictures have been combined in the following way (using Image Arithmetic Darkest option in PSP 6.02):

darkest of left and top
darkest of top and right

Then the above combinations are combined again (on the Image Arithmetic Lightest) and than brightness/contrast is changed (Color Adjust HMS and Color Adjust Brightness/Contrast):

lightest of above two
contrast and brightness changed

Any constructive ideas for improving the above methodology are very welcome!


I would like to thank the following people for their help and constructive feedback: Carl Bjork, Jeff Cooper and all the people who provided feedback on specific computer programs. Any remaining errors in methodology or results are my responsibility of course!!! If you want to provide constructive feedback, let me know.

Disclaimer and Copyright

Major content related changes: July 29, 2003