A Novel Photoshop-Based Digital Imaging Method for Measuring ColonyExtension of Biocontrol Fungi

Abstract

A cost-effective, simple and easy to use method was developed using scanned computer images and software programs to measure the colony extension area of biocontrol fungi on Petri dish. Data were collected daily and archived orderly onto a model sheet. This sheet was scanned and saved as JPEG form. Tracing areas in JPEG image were measured directly based on the integrated reference, using “Magic Wand tool” and “Histogram” in the Photoshop. Formula for calculating the pixel data was described. Low coefficient of variation and stable deviation rate were found. Therefore, this method would be of suitable and easy to handle for basic colony extension research.