Browse Prior Art Database

Buffering Input Data from a Touch or Pen-based Computer

IP.com Disclosure Number: IPCOM000014151D
Original Publication Date: 2000-Mar-01
Included in the Prior Art Database: 2003-Jun-19
Document File: 1 page(s) / 40K

Publishing Venue

IBM

Abstract

Disclosed is a plurality of memory buffers allocated from shared memory which is addressable by all applications in a pen or touch-based computer system. In the preferred embodiment, individual buffers are allocated to store pen/touch sensor resolution coordinates, display resolution coordinates, standard resolution (1/1000") coordinates, ink coordinates, auxiliary pen data and stroke information. These buffers consume in excess of 1 MB of RAM in the aggregate when the shared memory is allocated at system startup, however a minimum (typically 32KB) of the shared memory is actually committed which drastically reduces the amount of system working store.

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Buffering Input Data from a Touch or Pen-based Computer

Disclosed is a plurality of memory buffers allocated from shared memory which is addressable by all applications in a pen or touch-based computer system. In the preferred embodiment, individual buffers are allocated to store pen/touch sensor resolution coordinates, display resolution coordinates, standard resolution (1/1000") coordinates, ink coordinates, auxiliary pen data and stroke information. These buffers consume in excess of 1 MB of RAM in the aggregate when the shared memory is allocated at system startup, however a minimum (typically 32KB) of the shared memory is actually committed which drastically reduces the amount of system working store.

The size of the buffer pool is empirically derived. The 1 MB of memory allocated by present embodiment stores approximately 1365 strokes which equate to roughly 1000 handwritten characters requiring 40,000 ink points. Any single stroke can be up to 8000 points in length. Eight thousand points is equivalent to holding the pen down for 1 minute and 20 seconds which is reasonable if the user is drawing or shading.

The minimum and maximum size of each buffer is predetermined with the minimum sufficient to store any gesture and up to 12 text characters. As the user continues to write, the buffers are grown real-time by committing more memory. Once writing has ceased and recognition is performed, the extra memory is gradually decommitted until memory is once again at...