Display masks for display and calibration in projector-based display systems

An apparatus comprising:

• a camera to capture an image of a shape projected upon a display surface;
• and
• a bounding box module to generate a rectangular bounding box containing the shape,
• a display mask module to determine a first rectangle that is the largest inscribed rectangle for the shape in the captured image, comprising
• a section module to divide the rectangular bounding box vertically into first and second sections, and to divide the rectangular bounding box horizontally into third and fourth sections, and
• a rectangle module to determine
• a second rectangle that is the largest inscribed rectangle for the shape in the first section of the bounding box,
• a third rectangle that is the largest inscribed rectangle for the shape in the second section of the bounding box,
• a fourth rectangle that is the largest inscribed rectangle for the shape in a third section of the bounding box,
• a fifth rectangle that is the largest inscribed rectangle for the shape in the fourth section of the bounding box, and
• an edge module to select a top edge, and a bottom edge, of the first rectangle based on the second and third rectangles, and to select a left edge, and a right edge, of the first rectangle based on the fourth and fifth rectangles.

Tangible, non-transitory computer-readable media embodying instructions executable by a computer to perform a method comprising:

• receiving an image of a shape projected upon a display surface;
• and
• using a processor to generate a rectangular bounding box containing the shape and determine a first rectangle that is the largest inscribed rectangle for the shape in the captured image by
• dividing the rectangular bounding box vertically into first and second sections,
• determining a second rectangle that is the largest inscribed rectangle for the shape in the first section of the bounding box,
• determining a third rectangle that is the largest inscribed rectangle for the shape in the second section of the bounding box,
• dividing the rectangular bounding box horizontally into third and fourth sections,
• determining a fourth rectangle that is the largest inscribed rectangle for the shape in a third section of the bounding box,
• determining a fifth rectangle that is the largest inscribed rectangle for the shape in the fourth section of the bounding box,
• selecting a top edge, and a bottom edge, of the first rectangle based on the second and third rectangles;
• and
• selecting a left edge, and a right edge, of the first rectangle based on the fourth and fifth rectangles.