1. A method for tracking movement between a surface and an optical navigation device, the optical navigation device having an image sensor that includes an array of pixels, the method comprising: acquiring image information, the image information including pixel values that correspond to the pixels; calculating a surface quality (SQUAL) value from the image information; determining a level of saturation of the pixel array from pixel values of the image information; comparing the determined level of saturation of the pixel array to a saturation threshold; increasing a SQUAL threshold if the determined level of saturation of the pixel array is greater than the saturation threshold; and deciding whether or not to output motion tracking information in response to a comparison of the SQUAL value to the SQUAL threshold.