1. A non-transitory computer-readable medium having instructions stored thereon for assessing a quality of a microscope slide image, wherein the instructions, when executed by a processor, cause the processor to: acquire a plurality of focus point values for a sample on a microscope slide, wherein each of the plurality of focus point values comprises x-y coordinates indicating a location on the sample and a z coordinate indicating a focus height for the location on the sample; calculate a best-fit surface based on the plurality of focus point values; determine whether or not the plurality of focus point values comprise outlying focus point values, based on the best-fit surface and the z coordinate for one or more of the plurality of focus point values, by, at least in part, for each of the plurality of focus point values, removing a tilt from the best-fit surface and adjusting the focus point value, determining a distance between the adjusted focus point value and the untilted best-fit surface, and, if the distance is greater than a threshold value, determining that the focus point value is an outlying focus point value; and display a scanned image of the microscope slide within a graphical display, wherein the scanned image of the microscope slide comprises, for each of the outlying focus point values, an overlay that identifies the location on the sample of the outlying focus point value based on the x-y coordinates for the outlying focus point value, and wherein the graphical display provides access to a re-scan mode; and, when a user initiates the re-scan mode via the graphical display, initiate rescanning of the microscope slide.