A method of calibrating a display system, the method comprising: displaying a test pattern including a plurality of blobs; detecting one or more base blobs in the displayed test pattern; identifying, based on the detected base blobs, patches of the test pattern, wherein each patch comprises one of the base blobs and a subset of additional blobs detected in the displayed test pattern; determining a patch location for at least one patch within the test pattern based on the subset of the additional blobs in the patch to determine a blob location for at least one detected blob; determining a calibration parameter for the display system based on the blob location and a detected attribute of the at least one detected blob; and calibrating the projector using the calibration parameter.