Improving depth of field resolution for palynological photoMICROgraphy
Optical microscopy continues to be the preferred method for imaging in paleopalynology. While usefulness of other tools, such as the scanning electron microscope, is not questioned, the ease of use and timely results of optical microscopy remains unsurpassed. However, obtaining good quality photomicrographs requires the use of the highest magnifying power objectives available, which are inevitably associated with very limited depth of field. To avoid the need for multiple photomicrographs in order to fully describe each palynomorph, a software solution for reconstructing depth of field is proposed. This solution allows for keeping the main advantages of high magnifying power objectives (better resolution and improved contrast) while suppressing their main weakness. In addition, photomicrographs published using depth of field reconstruction have a more natural appearance, similar to when directly viewed with the eye under the microscope. While this paper deals primarily with the usage of depth of field reconstruction for the enhancement of palynological photomicrograph, the technique can be applied similarly to many other paleontological and geological objects as well.
Bercovici. UMR 6118 du CNRS, Géosciences Rennes, Bat. 15 – Université de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex, France.
Alan Hadley. 5 Ronald Road, Darnall,
Sheffield, United Kingdom
Uxue Villanueva-Amadoz. Departamento Ciencias de la Tierra (Paleontología), Universidad de Zaragoza. C/Pedro Cerbuna, 12. 50009
KEY WORDS: Image processing; optical microscopy; focus stacking;
palynology; depth of field reconstruction
PE Article Number: 12.2.5T
Copyright: Palaeontological Association August 2009
Submission: 18 September 2008. Acceptance: 14 May 2009