Fig. 8.

Analysis of constraints imposed by the chemical fluorescence process, using contrast-to-noise ratio (CNR) as the figure of merit. Photobleaching influences the choice between coded and strobed illumination only when introducing a coding scheme would cause photobleaching, corresponding to a thin area of strobed optimality near the photobleaching limit. This plot assumes no background autofluorescence, so CNR and SNR are equivalent. The amount of autofluorescence relative to the signal mean has a slight effect on the optimality of strobed and coded illumination, but the effect is not strong relative to the other parameters studied here. Generally, the presence of autofluorescence degrades CNR ratio for all methods and illumination levels.