1. A method of determining object position, comprising: determining an intensity value for each of a plurality of pixels; determining whether said each of a plurality of pixels is a higher intensity pixel which has the intensity value higher than a threshold or a lower intensity pixel which has the intensity value lower than the threshold; determining that a portion of the plurality of pixels belong to an object image corresponding to an object; and determining coordinate data of the object based on a number of pixels in each row or column of the portion of the plurality of pixels belonging to the object image and coordinates of pixels in the portion of the plurality of pixels belonging to the object image; wherein when there is at least one lower intensity pixel between two or more higher intensity pixels in a row or column and when the number of the at least one pixel is smaller than or equal to a predetermined number, said at least one lower intensity pixel between two or more higher intensity pixels is defined as part of the object image, and said at least one lower intensity pixel between two or more higher intensity pixels is defined as a pixel with intensity value higher than the threshold; or when there is at least one lower intensity pixel with intensity value lower than a threshold between two or more higher intensity pixels in a row or column and when there is no lower intensity pixel between two or more higher intensity pixels in an adjacent row or column, said at least one lower intensity pixel between two or more higher intensity pixels is defined as part of the object image, and said at least one lower intensity pixel between two or more higher intensity pixels is defined as a pixel with intensity value higher than the threshold.