“…Recent improvements in computer performance and reductions in the cost of digital imaging hardware and software, have contributed to the widespread use of digital image processing in biological and agricultural research. Digital image analysis has been applied to the quantitative evaluation of various features of biological organs, for example, in the assessment of various diseases (Lindow & Webb, 1983;Kampmann & Hansen, 1994;Tucker & Chakraborty, 1997;Martin & Rybicki, 1998;Martin et al, 1999;Niemira et al, 1999;Olmstead & Lang, 2001), measurement of plant canopies (Han & Hayes, 1990;Blackmer & Schepers, 1996;Adamsen et al, 1999;Ewing & Horton, 1999;Lukina et al, 1999;Purcell, 2000, Richardson et al, 2001Karcher & Richardson, 2003), and evaluation of tomato maturity (Choi et al, 1995;Polder et al, 2002). Despite the good progress in quantitative evaluation by digital imaging, no methods have yet demonstrated the effective evaluation of subtle variation in flower colour patterns.…”