Application of image processing programs in color analysis of wood photodegradation

Abstract

In general, polymer photodegradation is an important aspect of polymer science that is of great interest to chemistry, materials science, biology, and physics students who engage in this field of research. Wood consists of three main polymers, which makes it a good candidate for such photodegradation studies. Aside from structural changes based on chemical analysis, color change assessment can also be employed to check any extent of degradation on wood without the need for sophisticated analytical equipment. This study presents the application of two image processing programs in color analysis of wood photodegradation: ImageJ and Colormath library, which are Java-based and Python-based software, respectively. Images of unexposed and UV-exposed wood samples were taken using a smartphone as an affordable digital camera. RGB channel values from these images were analyzed and quantified by ImageJ software. These values were converted to the corresponding CIEL∗a∗b∗ parameters using the Colormath library to calculate the color change, ΔE. For the 3-hour exposed sample,?E is equal to 4.29. This value indicates appreciable color change, according to the criteria from literature. Regardless of the exposure time, the wood samples become darker as indicated by the negative value in the change in lightness L∗