Optimization of color print process control

Digital color print has become very popular with the quality improvement of colorants, paper, printers, print technology, etc. However, color shifts occur over time due to the variations in print environment, the complex interaction between paper and colorants, and the instability of printer physics. Commercial devices have been produced to calibrate color printers; they include spectrophotometer, colorimeter, and densitometer with calibration software. Three kinds of problems are inherent in these devices. Firstly, the cost of the device will be much higher for high quality calibration. For example, such a device would require an expensive spectrophotometer. Secondly, most calibration processes are time consuming as color patches are captured one by one using such devices，which constrain the productivity of the print process. Lastly but most importantly, the color output quality can be ensured only shortly after the calibration while the customers hope that the color quality could be maintained and remain predictable in the whole print process. Accordingly in this dissertation, these three problems will be addressed from the viewpoint of color sensing system, statistical paired comparison and color difference recognition, and dynamic programming and optimal control.Doctor of Philosophy (IMST