METHOD FOR DEFINING EFFECTIVE PIXELS IN IMAGE SENSING ARRAY

摘要

A method for defining effective pixels in an image sensing array of a light-shading optical touch system is proposed. First, light-shading objects are disposed at three end points of a touch panel, and a shaded image is generated by an image sensing array. Light-shading object pixels corresponding to the light-shading objects are obtained from the shaded image thereafter. Next, the light-shading objects are removed from the touch panel, and a non-shaded image is generated by the image sensing array. Three pixel columns corresponding to the end points are obtained from the non-shaded image, and a pixel with maximum intensity is obtained from each of the three pixel columns. Interpolated pixels between the three brightest pixels are obtained through interpolation from the non-shaded image. Image sensing pixels corresponding to the three brightest pixels and the interpolated pixels in the image sensing array are defined as effective pixels.

主权项

1. A method for defining effective pixels in an image sensing array, adapted to an optical touch system having at least one optical sensing module, a touch panel, and a backlight generator, wherein each of the at least one optical sensing module comprises a light source and an image sensing array, wherein the light source and the image sensing array are disposed at a reference endpoint of the touch panel, wherein the backlight generator is disposed at an edge of the touch panel, wherein the light source provides a sensing light beam, and wherein the method comprises:
disposing a light-shading object at each of a first endpoint, a second endpoint, and a third endpoint of the touch panel, and receiving backlight generated by the backlight generator due to the sensing light beam incident thereto by using the image sensing array so as to generate a shaded image, wherein the reference endpoint and the second endpoint are approximately diagonally opposite one another, and wherein the first endpoint and the third endpoint are approximately diagonally opposite one another; obtaining a plurality of light-shading object pixels corresponding to the light-shading objects from the shaded image; removing the light-shading objects from the touch panel, and receiving the backlight generated by the backlight generator by using the image sensing array so as to generate a non-shaded image; obtaining a first pixel column, a second pixel column, and a third pixel column respectively corresponding to the first endpoint, the second endpoint, and the third endpoint from the non-shaded image according to coordinates of the light-shading object pixels; obtaining a first pixel, a second pixel, and a third pixel with maximum intensity respectively from the first pixel column, the second pixel column, and the third pixel column; and obtaining a plurality of first interpolated pixels between the first pixel and the second pixel as well as a plurality of second interpolated pixels between the second pixel and the third pixel through an interpolation method, and defining a plurality of image sensing pixels in the image sensing array corresponding to the first pixel, the second pixel, the third pixel, the first interpolated pixels, and the second interpolated pixels as the effective pixels.