US 6,643,383 B1 · Method for hiding binary data in a digital image

Abstract

A method for hiding primary digital information in an initial digital document begins by first breaking down the initial document by determining a reference digital document as a function of the initial digital document by a fractal transformation method. Secondary digital information is created as a function of the primary digital information to be hidden and the reference digital document. A modified image is computed by the sum of the reference digital document and the secondary digital information such that the modified digital document approximates the initial document but integrating substantially indiscernible the primary digital information to be hidden. The method enables retrieval of digital information hidden in a multimedia document in a dual manner. The method is based on the concept of auto-similarity and ensures that the input information is not visible but finally be retrieved without providing knowledge of the original documents.

Claims51

Dependent claims

A process for hiding primary numerical information (Iinf1) inside an initial numerical document (Iorig), comprising the steps of:

generating a numerical document of reference (Iref) as a function of said initial numerical document (Iorig);
generating a gap image, said gap image being the difference between said initial numerical document (Iorig) and said numerical document of reference (Iref);
generating a secondary numerical information (Iinf2) as a function of said gap image and said primary numerical information (Iref) for hiding said primary numerical information (Iinf1);
and
adding said secondary numerical information (Iinf2) to said numerical document of reference (Iref) in order to obtain a modified initial numerical document (I′orig) close to the initial numerical document (Iorig), said modified initial document having no visual distortion from hiding the primary numerical information (Iinf1).

2 more elements

A process for extracting a primary numerical information Iinf1 from a modified initial numerical document (I′orig) which is assumed to host a hidden primary numerical information Iinf1, said process comprising the steps of:

computing a self-similarity code W′ associated to the modified initial numerical document (I′orig) by using a context utilized for computing said modified initial numerical document (I′orig);
retrieving a secondary numerical information (I′inf2) for each pixel from said modified initial numerical document (I′orig) and a self-similarity code (W′), said retrieving comprising the step of:
computing secondary numerical information (I′inf2) as a difference between modified initial numerical document (I′orig) and an attactor (A′), said attractor (A′) being defined by the self-similarity code (W′) associated to the modified initial numerical document (I′orig);
determining if said self-similarity code (W′) is contractive;
and
if said self-similarity code (W′) is contractive, testing the secondary numerical information I′inf2 and deducing I′inf1 as a function of a binary relationship between a gap difference and the primary numerical information (Iinf1).

3 more elements

A system that hides primary numerical information (Iinf1) inside an initial numerical document (Iorig), comprising:

a numerical document of reference (Iref) generator connected to receive said initial numerical document (Iorig) and for creating a numerical document of reference (Iref) as a function of the initial numerical document (Iorig);
a gap image generator connected to receive said initial numerical document (Iorig) and in communication with the a numerical document of reference (Iref) generator to receive said a numerical document of reference (Iref) to generate a gap image as the difference between said initial numerical document (Iorig) and said numerical document of reference (Iref);
a secondary numerical information (Iinf2) generator connected to receive the primary numerical information (Iinf1), in communication with the a numerical document of reference (Iref) generator to receive the a numerical document of reference (Iref), and in communication with the gap image generator to receive the gap image to determine a secondary numerical information (Iinf2) as a function of said gap image and said primary numerical information (Iref) to hide said primary numerical information (Iinf1);
and
a modified initial numerical document (I′orig) generator in communication with the a numerical document of reference (Iref) generator to receive the a numerical document of reference (Iref), in communication with the secondary numerical information (Iinf2) generator to receive secondary numerical information (Iinf2), said modified initial numerical document (I′orig) generator creating a modified initial numerical document (I′orig) by adding said secondary numerical information (Iinf2) to said numerical document of reference (Iref), said a modified initial numerical document (I′orig) closely approximating the initial numerical document (Iorig) without any visual distortion from hiding the primary numerical information (Iinf1).

2 more elements

A system for extracting a primary numerical information Iinf1 from a modified initial numerical document (I′orig) which is assumed to contain a hidden primary numerical information Iinf1, said system comprising:

a calculating device connected to receive the modified initial numerical document (I′orig) and from said modified initial numerical document (I′orig) computing a self-similarity code (W′) associated to the modified initial numerical document (I′orig) using a context utilized in originally computing said modified initial numerical document (I′orig) and said calculating device determining if said self-similarity code (W′) is contractive;
a secondary numerical information (I′inf2) extraction device connected to receive the modified initial numerical document (I′orig) and in communication with the calculating device for receiving the self-similarity code (W′) and from said modified initial numerical document (l′orig) and the self-similarity code (W′), said a secondary numerical information (I′inf2) extraction device computing secondary numerical information (I′inf2) as a difference between modified initial numerical document (I′orig) and an attactor (A′), said attractor (A′) being defined by the self-similarity code (W′) associated to the modified initial numerical document (I′orig);
and
a testing device in communication with the calculating device to receive an indication if said self-similarity code (W′) is contractive and in communication with the a secondary numerical information (I′inf2) extraction device, if said self-similarity code (W′) is contractive, said testing device tests the secondary
a gap image device connected to receive the original document (Iorig) and in communication with the reference document (Iref) generator to receive the reference document (Iref) for determining a gap image as a difference between said original document (Iorig) and said reference document (Iref);
a secondary numerical information (Iinf2) generator connected to receive said primary numerical information (Iinf1) and in communication with the gap image device, said secondary numerical information (Iinf2) generator determining a secondary numerical information (Iinf2) as a function of said gap image in accordance with a correspondence rule between said gap image and said primary numerical information (Iinf1);
and
a combining device in communication with the reference document (Iref) generator to receive the reference document (Iref) and in communication with the secondary numerical information (Iinf2) generator to receive the secondary numerical information (Iinf2), said combining device adding said secondary numerical information (Iinf2) to said reference document (Iref) in order to produce a modified document (I′orig) substantially close to said original document (Iorig).

5 more elements

A medium for retaining a computer program which, when executed by a computing system, performs a program process for hiding a primary numerical information (Iinf1) inside an initial numerical document (Iorig), said process comprising the steps of:

generating a numerical document of reference (Iref) being a function of said initial numerical document (Iorig);
generating a gap image, said gap image being the difference between said initial numerical document (Iorig) and said numerical document of reference (Iref);
generating a secondary numerical information (Iinf2) as a function of said gap image and said primary numerical information (Iref) to hide said primary numerical information (Iinf1);
and
adding said secondary numerical information (Iinf2) to said numerical document of reference (Iref) in order to obtain a modified initial numerical document (I′orig) close to the initial numerical document (Iorig), said modified initial document having no visual distortion from hiding the primary numerical information (Iinf1).

2 more elements

A medium for retaining a computer program which, when executed by a computing system, performs a program process for extracting a primary numerical information Iinf1from a modified initial numerical document (I′orig) which is assumed to host a hidden primary numerical information Iinf1, said program process comprising the steps of:

computing a self-similarity code W′ associated to the modified initial numerical document (I′orig) by using a context utilized for computing said modified initial numerical document (I′orig);
retrieving a secondary numerical information (I′inf2) for each pixel from said modified initial numerical document (I′orig) and a self-similarity code (W′), said retrieving comprising the step of:
computing secondary numerical information (I′inf2) as a difference between modified initial numerical document (I′orig) and an attactor (A′), said attractor (A′) being defined by the self-similarity code (W′) associated to the modified initial numerical document (I′orig);
determining if said self-similarity code (W′) is contractive;
if said self-similarity code (W′) is contractive, testing the secondary numerical information I′inf2 and deducing I′inf1 as a function of a binary relationship between a gap difference and the primary numerical information (Iinf1).

2 more elements

A medium for retaining a computer program which, when executed by a computing system, performs a program process for hiding a primary numerical information (Iinf1) inside an original document (Iorig), said program process comprising the steps of:

determining a reference document Iref by means of a lossy approximation transformation method upon said original document (Iorig);
determining a gap image being equal to a difference between said original document (Iorig) and said reference document (Iref);
determining a secondary numerical information (Iinf2) computed as a function of said gap image in accordance with a correspondence rule between said gap image and said primary numerical information (Iinf1);
and
adding said secondary numerical information (Iinf2) to said reference document (Iref) in order to produce a modified document (I′orig) substantially close to said original document (Iorig).

2 more elements

Dependencies are inferred from the claim text.

Method for hiding binary data in a digital image

Life of this patent

Method for hiding binary data in a digital image

Life of this patent

Abstract

Claims51