Patent ID: 8681125

Claim:
A method for estimating the tendency of pressure change on a touch panel, used in an optically-detected input image system, the optically-detected input image system comprises a left image-capturing device and a right image-capturing device for detecting a position touched on an image screen by a user, the method comprising: at a first time, obtaining first left image data by using the left image-capturing device, and obtaining first right image data by using the right image-capturing device; calculating a first estimated pressed-area parameter according to the first left image data and the first right image data; at a second time, obtaining second left image data by using the left image-capturing device, and obtaining second right image data by using the right image-capturing device; calculating a second estimated pressed-area parameter according to the second left image data and the second right image data; and comparing the first estimated pressed-area parameter with the second estimated pressed-area parameter for performing one of the following steps: if the second estimated pressed-area parameter is greater than the first estimated pressed-area parameter, determining the user increases a touch pressure on the image screen from the first time to the second time; and if the second estimated pressed-area parameter is less than the first estimated pressed-area parameter, determining the user decreases the touch pressure on the image screen from the first time to the second time.