Watermarked image generation apparatus, watermarked image analysis apparatus, watermarked image generation method, medium and computer readable medium

Abstract

A watermarked image generation apparatus embeds target data in an original image to generate a watermarked image. The watermarked image generation apparatus includes a target-data embedding unit and a marker-image embedding unit. The target-data embedding unit embeds the target data in respective plural embedding areas contained in the original image, to generate a watermarked image. The marker-image embedding unit embeds in the watermarked image a plurality of marker images used for identifying the plurality of embedding areas.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention will be described in detail based on the following figures, wherein:

FIG. 1 is a block diagram to show the schematic configurations of a watermarked image generation apparatus and a watermarked image analysis apparatus according to an exemplary embodiment of the invention;

FIG. 2 is a flowchart to show an example of processing executed by the watermarked image generation apparatus according to the exemplary embodiment of the invention;

FIG. 3 is a schematic representation to show an example of a watermarked image generated by the watermarked image generation apparatus according to the exemplary embodiment of the invention;

FIG. 4 is a flowchart to show an example of processing executed by the watermarked image analysis apparatus according to the exemplary embodiment of the invention; and

FIG. 5 is an explanatory diagram to show examples of a captured image provided by the watermarked image analysis apparatus according to the exemplary embodiment of the invention and an embedding area.

Claims

1. A watermarked image generation apparatus for embedding target data in an original image to generate a watermarked image, the watermarked image generation apparatus comprising: a target-data embedding unit that embeds the target data in respective plural embedding areas contained in the original image, to generate a watermarked image; anda marker-image embedding unit that embeds in the watermarked image a plurality of marker images used for identifying the plurality of embedding areas.

2. The apparatus according to claim 1, wherein at least one of the marker images is used for identifying at least some of the embedding areas.

3. The apparatus according to claim 1, further comprising: a density adjustment unit that changes a density of a non-embedding area, which is an area in the watermarked image other than the embedding areas.

4. The apparatus according to claim 3, wherein the density adjustment unit embeds dummy data in the non-embedding area to change the density of the non-embedding area.

5. The apparatus according to claim 3, wherein: the density adjustment unit acquires a change amount of a density of the embedding areas between before and after the target-data embedding unit embeds the target data in the embedding areas, andthe density adjustment unit changes the density of the non-embedding area based on the acquired change amount of the density of the embedding areas.

6. The apparatus according to claim 2, further comprising: a density adjustment unit that changes a density of a non-embedding area, which is an area in the watermarked image other than the embedding areas.

7. The apparatus according to claim 6, wherein the density adjustment unit embeds dummy data in the non-embedding area to change the density of the non-embedding area.

8. The apparatus according to claim 6, wherein: the density adjustment unit acquires a change amount of a density of the embedding areas between before and after the target-data embedding unit embeds the target data in the embedding areas, andthe density adjustment unit changes the density of the non-embedding area based on the acquired change amount of the density of the embedding areas.

9. A watermarked image analysis apparatus for extracting target data from a watermarked image generated by embedding the target data in respective plural embedding areas contained in an original image, the watermarked image analysis apparatus comprising: an image capturing unit that captures at least a part of the watermarked image to provide a captured image;an identifying unit that identifies a plurality of partial embedding areas contained in the captured image, each of the partial embedding areas being a portion of the embedding area;an extraction unit that analyzes at least some of the plurality of partial embedding areas, the extraction unit that extracts plural pieces of partial target data, each of the pieces of partial target data being a portion of the target data; anda target data re-generating unit that combines the extracted pieces of partial target data to re-generate the target data.

10. A watermarked image generation method to embed target data in an original image to generate a watermarked image, the method comprising: embedding the target data in respective embedding areas contained in the original image to generate a watermarked image; andembedding a plurality of marker images used for identifying the plurality of embedding areas in the watermarked image.

11. A medium formed with a watermarked image, the medium comprising: a plurality of embedding areas in which respective plural watermarked images are embedded; anda plurality of marker images used for identifying the plurality of embedding areas.

12. A computer readable medium storing a program causing a computer to execute a process for embedding target data in an original image to generate a watermarked image, the process comprising: embedding the target data in respective plural embedding areas contained in the original image, to generate the watermarked image; andembedding in the watermarked image a plurality of marker images used for identifying the plurality of embedding areas.

13. A computer data signal embodied in a carrier wave for enabling a computer to perform a process for embedding target data in an original image to generate a watermarked image, the process comprising: embedding the target data in respective plural embedding areas contained in the original image, to generate the watermarked image; andembedding in the watermarked image a plurality of marker images used for identifying the plurality of embedding areas.