SYSTEM FOR VERIFYING IMAGES
    3.
    发明专利

    公开(公告)号:JP2002314799A

    公开(公告)日:2002-10-25

    申请号:JP2002025323

    申请日:2002-02-01

    Applicant: IBM

    Abstract: PROBLEM TO BE SOLVED: To provide a system which quickly verifies that the content of an image has not been changed since an earlier time, when the content of that image was stamped. SOLUTION: The system consists of a stamping process that embeds stamping information into a source image and produces a verification key, and a verification process that extracts stamping information from a stamped source image based on the verification key. Furthermore, the verification process produces an image itself, from which the verification can be readily judged visually or by the use of a computer or other display device. In the verification process, the changes in an image can be detected and localized. In the stamping process, an image is safeguarded against malicious manipulations, and the proprietary rights are protected by maintaining the integrity of the image content.

    PICTURE VERIFICATION DEVICE
    5.
    发明专利

    公开(公告)号:JPH10208026A

    公开(公告)日:1998-08-07

    申请号:JP33675797

    申请日:1997-12-08

    Applicant: IBM

    Abstract: PROBLEM TO BE SOLVED: To verify that contents of a picture are not changed after being stamped by discriminating alteration of the stamped picture at the time extracted stamping information is unmatching with source stamping information. SOLUTION: A picture server 108 verifies the integrity of picture data stored in a picture archive 106. That is, a source picture 104 stamped from the archive is selected, and each information is read into a calculation device after a verification key 105 corresponding to a picture stamped from a key protection storage device 107 is acquired. In the verification processing, the stamped source picture and the verification key are processed to extract stamping information embedded in the picture. Next, extracted stamping information and stamping information 100 known by the server are compared with each other. If they coincide with each other, it is judged that this picture is not changed after being stamped. This verification result is used to confirm the integrity of contents, and a proper processing is performed if it is verified that contents have been changed.

    METHOD FOR IMPARTING AND DETECTING WATERMARK

    公开(公告)号:JPH10191017A

    公开(公告)日:1998-07-21

    申请号:JP29209097

    申请日:1997-10-24

    Applicant: IBM

    Abstract: PROBLEM TO BE SOLVED: To impart an invisible identification mark on an image and to make elimination impossible by a normal means by multiplying a prescribed luminance magnification to the luminance data of the respective pixels of digitized images and performing watermarking. SOLUTION: Image data 101 fetched from a physical source 102 by a scanner 100 are sent to a digital computer 104. By a (front end) image processing 112, scaling and expansion, etc., are performed and they are kept in an archive 110. Then, after performing the watermarking by the watermarking 114, compression or the like on a screen is performed in a (back end) image processing 116 and then, they are kept in a work storage area 106 and an image storage area 108. In the watermarking, the prescribed luminance magnification of 0.9-1.1 is multiplied to the luminance data of the pixels on the images. The watermarked image data are sent through an image server 118 to a digital network 120 and outputted by a display device 124 and a printer 126.

    9.
    发明专利
    未知

    公开(公告)号:DE69118162T2

    公开(公告)日:1996-10-02

    申请号:DE69118162

    申请日:1991-12-06

    Applicant: IBM

    Abstract: A system and method for improving the quality of the output of a full-color image on a reproduction device, such as a display on a monitor or printout from a printer, that only consists of a small number of colors in comparison to the number of colors represented by the input signals. The disclosure involves specifying a new quantization method for multi-color images, rendered with orthogonal or separable color image palettes, that takes advantage of the calculations done by error diffusion. Accordingly, the image input signals are processed using the quantization error generated by one color component of a given pixel to influence the quantization of subsequent color components of the same pixel, and in such a way that the color image, so rendered, appears less grainy.

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