Systems and methods which obtain template images corresponding to pattern units of tessellated images using a template unit boundary identification technique are described. Template unit boundary identification techniques of embodiments operate to analyze a sample of a tessellated image to determine a template unit size for the template image, use the determined template unit size to define pixel analysis line segments for identifying template unit boundaries in the tessellated image, and select a template image based on the template unit boundaries identified using the pixel analysis line segments. One or more sample area images may be selected for use in determining a template unit size. Pixel analysis line segments, configured based upon a determined template unit size, may be used for identifying boundaries of a template unit. Moreover, dynamic template image updating may be provided.