A method for analyzing a dipstick using a smartphone is provided herein. The method includes: capturing an image containing: a dipstick having colored test reagents, and a color board having a grid of grey patches and a plurality of reference color patches; deriving, based on the grid, local illumination parameters associated with the colored test reagents and the plurality of reference color patches; determining whether illumination parameters are sufficient for interpreting the colored test reagent; in a case the illumination parameters are insufficient, notifying a user that an interpretation of the colored test reagents is not possible, otherwise, applying one or more image enhancement operation to the captured image, based on an analysis of the grid of grey patches, to yield enhanced reference color patches; and interpreting the one or more colored test reagents, by projecting the colored test reagents onto a vector of the enhanced reference color patches.