Design and Calibration of a Software-based Food Colorimeter System

In this study the factors controlling the software colorimetry (Photoshop), including illumination (direct and indirect), image background (white and black), camera settings (zoom, light, resolution and environmental conditions) and the conversion equations of R, G, B images to L *, a *, b *, compared with the results of the device were investigated and optimized. The results showed that the factors affecting the photography which werw found to be just the background color and light setting of camera would have the most significant effect on software colorimetery and white background and indirect illumination were the best conditions. significant difference was observed between software and instrumentally colorimetry after optimization the effective factors on photography also relationships used in the conversion were not careful enough. Therefore in consideration of the difference between physical characteristics of foods surface with a color chart (used to optimize the imaging conditions) it is necessary for optimization a software colorimetery system to use the regression between software and device colorimetry results of test foods.