Passive touch system and method of detecting user input
AssigneeSMART Technologies ULC
InventorsGERALD MORRISON, MAVINDER SINGH
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Abstract
A passive touch system includes a passive touch surface and at least two cameras associated with the touch surface. The at least two cameras acquire images of the touch surface from different locations and have overlapping fields of view. A processor receives and processes images acquired by the at least two cameras to detect the existence of a pointer therein and to determine the location of the pointer relative to the touch surface. Actual pointer contact with the touch surface and pointer hover above the touch surface can be determined.
Claims17
A method comprising:
- acquiring first and second images from different viewpoints;
- subtracting said first and second images from background images to form first and second difference images;
- processing each of said first and second difference images to determine if a region of interest within the difference image including a pointer exists therein, said region of interest being based on summed pixel intensities exceeding a threshold;
- for each region of interest, masking the pixels of the region of interest to contrast pixels representing the pointer from pixels representing the background;
- determining a position of the pointer based on pointer information calculated from the regions of interest;
- and
- controlling an application based on the determined position of the pointer.
An apparatus comprising:
- cameras configured to acquire first and second images from different viewpoints;
- and at least one processor configured to:
- subtract said first and second images from background images to form first and second difference images;
- process each of said first and second difference images to determine if a region of interest within the difference image including a pointer exists therein, said region of interest being based on summed pixel intensities exceeding a threshold;
- for each region of interest, mask the pixels of the region of interest to contrast pixels representing the pointer from pixels representing the background;
- determine a position of the pointer based on pointer information calculated from the regions of interest;
- and
- control an application based on the determined position of the pointer.
A non-transitory computer-readable medium embodying computer program code that, when executed, causes an apparatus at least to:
- acquire first and second images from different viewpoints;
- subtract said first and second images from background images to form first and second difference images;
- process each of said first and second difference images to determine if a region of interest within the difference image including a pointer exists therein, said region of interest being based on summed pixel intensities exceeding a threshold;
- for each region of interest, mask the pixels of the region of interest to contrast pixels representing the pointer from pixels representing the background;
- determine a position of the pointer based on pointer information calculated from the regions of interest;
- and
- control an application based on the determined position of the pointer.
Dependencies are inferred from the claim text.