Auto-aligning touch system and method

A touch system comprising:

• a touch screen having a touch surface on which an image is displayed;
• at least one camera acquiring images of said touch surface including said displayed image;
• a pointer contact data generator generating pointer position data in response to pointer contact with said touch surface, said pointer position data representing the location of said pointer on said touch surface where pointer contact is made;
• and
• a processor communicating with said at least one camera and said pointer contact data generator, said processor using reference marks in said displayed image to calibrate automatically co-ordinate systems of said touch system by mapping an existing co-ordinate system of said touch screen to the displayed image co-ordinate system, and using calibrated pointer position data to update image data that is used to present the displayed image on said touch surface, wherein said processor compares the acquired images of said touch surface with a library of reference mark data to identify the reference marks in said acquired images, calculates the locations of said identified reference marks in the touch screen co-ordinate system using triangulation and uses the calculated locations to map the touch screen co-ordinate system to the displayed image co-ordinate system, said mapping being used to calibrate the pointer position data prior to updating said image data.

A method of updating image data used to present a displayed image on a touch surface in response to pointer contact on said touch surface, said method comprising:

• displaying a desktop image on said touch surface, at least one display element of said desktop image representing a reference mark;
• acquiring images of said touch surface including said displayed image;
• identifying said at least one reference mark in acquired images by comparing said acquired images with a library of reference marks and determining the location of said at least one reference mark;
• generating pointer contact data in response to pointer contact with said touch surface;
• automatically mapping touch surface and display co-ordinate systems using the determined location of said at least one reference mark on an on-going basis to calibrate the touch surface in real-time;
• and
• updating image data used to present the displayed image on said touch surface using pointer contact data that has been calibrated using said mapping.

A touch system comprising:

• a touch screen having a touch surface on which an image is displayed;
• at least one camera acquiring images of said touch surface including said displayed image;
• a pointer contact data generator generating pointer position data in response to pointer contact with said touch surface, said pointer position data representing the location of said pointer on said touch surface where pointer contact is made;
• and
• a processor communicating with said at least one camera and said pointer contact data generator, said processor using reference marks in said displayed image to calibrate automatically co-ordinate systems of said touch system, and using calibrated pointer position data to update image data that is used to present the displayed image on said touch surface, wherein said processor calculates the distances between a known edge of said touch surface and said reference marks in raw camera pixels to determine the locations of the reference marks in the touch screen co-ordinate system.

In a touch system having a touch screen with a touch surface on which an image is displayed, a method of automatically mapping a touch screen co-ordinate system to the display co-ordinate system comprising the steps of:

• including in said displayed image a plurality of reference marks, the location of the reference marks in said display co-ordinate system being known;
• acquiring an image of said touch surface including said displayed image;
• determining the locations of said reference marks in said acquired image relative to said touch screen co-ordinate system by calculating the distances between a known edge of said touch surface and said reference marks in raw camera pixels;
• and
• automatically mapping said touch screen co-ordinate system to said display co-ordinate system using said determined locations and the locations of the reference marks in said display co-ordinate system.

A touch system comprising:

• a touch screen having a touch surface on which a desktop image is displayed, at least one display element of said desktop image representing a reference mark;
• at least one camera acquiring images of said touch surface including said displayed image;
• a pointer contact data generator generating pointer position data in response to pointer contact with said touch surface, said pointer position data representing the location of said pointer on said touch surface where pointer contact is made;
• and
• a processor communicating with said at least one camera and said pointer contact data generator, said processor automatically calibrating co-ordinate systems of said touch system generally continually during operation of said touch system by comparing each acquired image with a database of reference marks to identify and locate the at least one reference mark in each acquired image and using the at least one reference mark location to map the touch screen coordinate system to the display coordinate system, said processor using calibrated pointer position data to update image data that is used to present the displayed image on said touch surface.