Patent attributes
Automated camera-based optical assessment involves color assessment of a physical object using conventional and inexpensive computer hardware such as a smartphone. A specially-configured test card includes a body supporting a reagent pad configured to change to an expected color in response to an enzymatic reaction, and an imaging key adjacent the reagent pad. The imaging key includes color fields including at least one field of the expected color. The hardware captures an image of the test card, and processes the image to identify the reagent pad and color fields, to process a brightness calibration target, to determine color values for the reagent pad and color fields, to calibrate the color values as a function of brightness and/or color by comparison to the brightness and color calibration targets, and to identify a color field most closely matching the reagent pad's color to determine a corresponding test result.