Method of calibrating a computerized leveling offset meter

A processor configured to execute a series of operations for calibrating a levelling offset meter (LOM) for calculating the angular offset between a plane parallel to the LOM and a predetermined reference plane, the LOM comprising a bull's eye spirit level having a bubble therein, the processor operatively coupled to an imager configured to image the spirit level, the series of operations comprising:

• calculating, in respect of each of a plurality of images of the spirit level image, a pixel distance from the bubble center to a predetermined zero offset pixel, thereby obtaining in respect of the plurality of images a plurality of pixel distances, each pixel distance associated with a known angular offset, each image being captured by the imager while the LOM is oriented with respect to the predetermined reference plane at the known angular offset associated with the image;
• fitting a function to a plurality of pairs of values, each pair of values comprising a pixel distance and its associated known angular offset, said function being useable to map a new pixel distance obtained in respect of a new image to a corresponding angular offset between a plane parallel to the LOM and the predetermined reference plane;
• and
• storing the function in a memory.

A computer program product comprising a program of instructions readable by a computer, the program of instructions for executing a method of calibrating a levelling offset meter (LOM) for calculating the angular offset between a plane parallel to the LOM and a predetermined reference plane, the LOM comprising a bull's eye spirit level having a bubble therein, and a processor operatively coupled to an imager, the method comprising:

• capturing, by the imager, a plurality of images of the spirit level, the plurality of images associated with a respective plurality of known angular offsets, each image being captured while the LOM is oriented with respect to the predetermined reference plane at the known angular offset associated with the image;
• calculating, by the processor, in respect of each image, a pixel distance from the bubble center to a predetermined zero offset pixel, thereby obtaining in respect of the plurality of images a plurality of pixel distances, each pixel distance associated with a known angular offset;
• fitting, by the processor, a function to a plurality of pairs of values, each pair of values comprising a pixel distance and its associated known angular offset, said function being useable to map a new pixel distance obtained in respect of a new image to a corresponding angular offset between a plane parallel to the LOM and the predetermined reference plane;
• and
• storing the function in a memory.