International Business Machines Corporation

Toshiroh Tabata

Masaya Mori

Hiroji Itoh

Shigeru Matsubara

Tohru Mori

Since the surface of the touch panel is often slippery, pressure points of the writing stylus on a touch panel may easily skip along the input contiguous line. The present invention calculates the velocity of writing stylus movement at each segment of the input contiguous line from a touch location and detection time of each touch which may be detected at intervals, produces a line drawing which connects each pair of touch locations of touches that are temporally adjacent in the detection order with a line of a type determined based on the calculated velocity, and displays the line drawing on the LCD.

Pressure sensitive writing tablet, control method and control program therefor

An area fill technique for graphic images is disclosed wherein the contour lines constituting an image are given in a series of line segments or a series of vectors, and horizontal line segments are ignored. Each line segment other than the horizontal ones is specified by the coordinate addresses for the start and end points in one direction, that is, from top to bottom or from bottom to top. Each is then converted into approximate pixels in the X-Y coordinate system, and stored in a random access work memory. The pixels of each line segment are stored in the work memory according to a rule whereby each line segment is represented by one pixel per horizontal line, and is written by taking exclusive OR of its pixels, excluding the start point, with read pixel data at corresponding coordinate addresses in the work memory. Thus, an even number of contour line pixels exist in each horizontal line in the work memory, and, area fill can be realized by scanning each horizontal line in the work memory and turning on pixel memory cells from an odd numbered contour line pixel to an even numbered contour line pixel. This technique makes it possible to easily perform area fill even for complicated images.

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Kyouto, Japan

Toshiroh Tabata