1. A computing system for removing digital watermarks from a watermarked image, the computing system comprising: a storage device operable to store a plurality of watermarked images; and a least one processor operable to execute a digital watermarks removing system, comprising: an image retrieving module operable to retrieve a watermarked image from the storage device; an image decomposing module operable to decompose the watermarked image to a plurality of Eigen-images, and assign an identifier to each of the Eigen-images in sequence; an image identifying module operable to identify an identifier range of the Eigen-images to be removed from the watermarked image, wherein the image identifying module is further operable to: convert the watermarked image into a just noticeable distortion (JND) image by using a JND algorithm; calculate a JND value of each pixel point in the JND image, and calculating an average value of all the JND values; compare the JND value of each pixel point with the average value; select each pixel point of the JND image whose JND value is greater than the average value as an Eigen-point of the Eigen-image; analyze an eigen value for each of the Eigen-points in all the Eigen-images; and select each Eigen-image whose eigen value of each Eigen-point is similar to the JND value, and putting the identifier of the selected Eigen-images to the identifier range; an image selecting module operable to calculate an eigen value of each Eigen-point in each Eigen-image, obtain a total eigen value of each Eigen-image by adding the eigen values of all the Eigen-points in each Eigen-image, and select Eigen-images having watermarked information from the Eigen-images within the identifier range according to the total eigen values; and a watermarked information deleting module operable to delete the selected Eigen-images from the Eigen-images within the identifier range, integrate the remainder Eigen-images of the identifier range to obtain a composite image, and store the composite image in the storage device.