1. A method for identifying platelets within a substantially undiluted whole blood sample, comprising: adding at least one fluorescent colorant to the whole blood sample which colorant is operable to tag the platelets; imaging at least a region of the whole blood sample quiescently residing within a chamber to create at least one region image, which region image has an area, and which imaging includes illuminating at least a portion of the quiescent sample with one or more first wavelengths of light in a manner that causes the fluorescent colorant to emit at least one second wavelength of light, and which image comprises per incremental units, each per incremental unit having an intensity value representative of the at least one second wavelength of light emitted relative to that per incremental unit; identifying one or more peak intensity values within local sub-regions of the at least one region image using the per incremental unit intensity values, which local sub-regions are each of a predetermined area less than the region area; and identifying one or more platelets within the whole blood sample, which identifying includes comparing per incremental unit intensity values in a respective local sub-region to distinguish per incremental unit intensity values associated with plasma from per incremental unit intensity values associated with platelets.