Pilot study on associating pen pressure with pen holding position using three-dimension property of stroke indentation

Objectives: The author collected several samples with Chinese characters and utilized the 3D property of stroke indentation to explore how pen strokes left on the paper can assist with forensic investigation. Methods: We chose to collect the three-dimension property of handwriting strokes and analyze strokes indentation. In this study, the author extracted stroke indentation through focus variation microscopy as implemented by AB8000. Results and Conclusion: Upon experimenting with different types of pens and different writing surface, the author found that this result can tell with a great degree of certainty whether the sample is formed with a left-hand or right-hand writer and how the pen was being held. Although there are variations among the test results, the discovered pattern generally holds for different types of pens and writing surfaces, except that the result from using felt tip pens or extremely hard surfaces are less satisfactory. These findings are expected to be able to assist in narrowing down who wrote a certain handwriting sample.