Parallel touch point detection using processor graphics

A computing device for touch point centroid detection, the computing device comprising:

• a touch screen;
• an input frame module to receive an input frame from the touch screen, the input frame defining a plurality of cells, each cell having a touch data value;
• and
• a centroid detection module to:
• group the cells of the input frame into a plurality of blocks;
• search for a local maximum cell within each of the plurality of blocks, the local maximum cell having a touch data value having a predefined relationship with a signal threshold value;
• identify each of the local maximum cells as a centroid;
• merge centroids that are located within a touch distance threshold of each other;
• and
• detect a cluster boundary around each of the merged centroids, each cluster boundary to include at least one cell of the input frame.

A method for detecting touch point centroids on a computing device, the method comprising:

• receiving, on the computing device, an input frame from a touch screen of the computing device, the input frame defining a plurality of cells, each cell having a touch data value;
• grouping, on the computing device, the cells of the input frame into a plurality of blocks;
• searching, on the computing device, for a local maximum cell within each of the plurality of blocks, the local maximum cell having a touch data value having a predefined relationship with a signal threshold value;
• identifying, on the computing device, each of the local maximum cells as a centroid;
• merging, on the computing device, centroids that are located within a touch distance threshold of each other;
• and
• detecting, on the computing device, a cluster boundary around each of the merged centroids, each cluster boundary including at least one cell of the input frame.

One or more machine readable storage media comprising a plurality of instructions that in response to being executed cause a computing device to:

• receive an input frame from a touch screen of the computing device, the input frame defining a plurality of cells, each cell having a touch data value;
• group the cells of the input frame into a plurality of blocks;
• search for a local maximum cell within each of the plurality of blocks, the local maximum cell having a touch data value having a predefined relationship with a signal threshold value;
• identify each of the local maximum cells as a centroid;
• merge centroids that are located within a touch distance threshold of each other;
• and
• detect a cluster boundary around each of the merged centroids, each cluster boundary including at least one cell of the input frame.

A computing device for touch point tracking, the computing device comprising:

• a touch screen;
• an input frame module to (i) receive a previous input frame from the touch screen, the previous input frame defining a plurality of cells identifying a plurality of previously tracked touch points and (ii) receive a current input frame from the touch screen, the current input frame defining a plurality of cells and identifying a plurality of current touch points;
• and
• a touch point tracking module to:
• predict a location of each of the plurality of previously tracked touch points identified in the previous input frame;
• assign an identifier of a previously tracked touch point to a current touch point having a current location within a tracking distance threshold of the predicted location of the previously tracked touch point;
• remove duplicate identifiers assigned to the current touch points;
• assign each unassigned identifier of the previously tracked touch points to a current touch point (i) that is the closest current touch point to the previously tracked touch point within the tracking distance threshold and (ii) that has not previously been assigned an identifier of the previously tracked touch points;
• and
• assign a unique identifier to each unassigned current touch point.