A method and apparatus for analyzing white blood cells (WBCs) within a whole blood sample quiescently residing within a chamber is provided. The chamber is defined by at least one transparent panel, and the whole blood sample includes at least one colorant operable to differentially identify at least one WBC type from another WBC type within the sample. The method includes the steps of: a) creating at least one image of the sample quiescently residing within the chamber; b) identifying portions of the sample image, with each portion representing a single WBC; c) compressing the sample image portions using a first compression algorithm; and d) one of compressing a remainder of the sample image not included in the portions using a second compression algorithm, or discarding the remainder.