KR20120088402A

KR20120088402A - Digital Wartermarking Method and Device for Accuracy and Topology of Vector Map Data

Info

Publication number: KR20120088402A
Application number: KR1020110009735A
Authority: KR
Inventors: 한경희
Original assignee: 주식회사 마크애니
Priority date: 2011-01-31
Filing date: 2011-01-31
Publication date: 2012-08-08

Abstract

PURPOSE: A digital watermarking method in consideration of accuracy and the phase of vector map data and a device thereof are provided to reflect accuracy and the phase of digital map data to the digital watermarking method. CONSTITUTION: A digital map watermark inserting machine(100) inserts a watermark into a digital map. A digital map corrector(200) corrects a digital map error. A digital map watermark extractor(300) extracts a watermark from a watermark digital map. A watermark verifier(400) verifies the extracted watermark. It is determined whether a digital map exists in an allowable error range after the watermark is inserted. If the digital map is out of the allowable error range, the digital map is corrected to exist in the allowable error range.

Description

Digital watermarking method and device considering accuracy and phase of vector map data {Digital Wartermarking Method and Device for Accuracy and Topology of Vector Map Data}

The present invention relates to a method and apparatus for inserting additional information that can prove ownership while maintaining accuracy and phase relationship for copyright protection of vector member data.

Conventional digital map watermarking technology introduces a watermarking algorithm for maintaining the accuracy of phase relations and data due to watermark embedding, but does not consider the current situation.

The present invention has been made to solve such a problem, and an object thereof is to provide a method and an apparatus capable of reflecting the accuracy and phase of digital map data.

In order to achieve the above object, the present invention determines that a digital map does not exist in the tolerance range after the watermark is inserted after buffering the numerical map before the watermark is inserted and is out of the tolerance range. Correct it so that it is out of range so that the accuracy and phase of the digital map is maintained.

The digital watermarking apparatus includes a digital map watermark inserter for inserting a watermark into a digital map, a digital map compensator for correcting a digital map error (accuracy), and a digital map watermark for extracting a watermark from a watermarked digital map. An extractor and a watermark verifier for verifying the extracted watermark.

According to the present invention, it is possible to insert additional information that can prove ownership while maintaining the accuracy and topological relationship in copyright protection of the vector map data.

1 is a block diagram illustrating a system for inserting a digital map watermark reflecting digital map accuracy and phase.
2 is a flowchart illustrating a flow for inserting a digital map watermark reflecting the digital map accuracy and phase.
3 is a schematic diagram illustrating a method of finding an area deviating from an error range of a digital map having a watermark embedded therein.
4 is a schematic diagram of the contents buffered from the original digital map, the watermarked digital map, and the watermarked digital map.
FIG. 5 is a schematic diagram illustrating a method of correcting vertex coordinates out of a tolerance range of a digital map in a watermarking algorithm in which a watermark is inserted using valid values of vertex coordinate values.
FIG. 6 is a schematic diagram illustrating a method of correcting coordinates outside the tolerance range of a digital map in a watermark algorithm in which a vertex is added between a vertex and a vertex to insert a watermark.

Hereinafter, with reference to the drawings will be described.

1 is a block diagram showing a system for inserting a digital map watermark reflecting the accuracy and phase of the digital map, wherein the system is a digital map watermark inserter 100 for inserting a watermark on the digital map; Digital map corrector 200 for correcting errors (accuracy), digital map watermark extractor 300 for extracting a watermark from the watermarking numerical map, watermark verifier 400 for verifying the extracted watermark do.

Figure 1 (a) shows a process of inserting a watermark on the numerical map. When the numerical map data is input to insert the watermark into the watermark inserter 100, the watermark is inserted into the numerical map. The digital map corrector 200 corrects the digital map in which the watermark is inserted within an error tolerance range. The watermark extractor 300 extracts a watermark from the corrected watermark numerical map. The watermark verifier 400 verifies whether the extracted watermark is normal.

Figure 1 (b) shows a process of extracting a watermark from the watermark numerical map. The watermark extractor 500 receives the watermark numerical map data, extracts the watermark, and verifies whether the watermark extractor is a normal watermark through the watermark verifier 600.

2 is a schematic diagram showing a flow for inserting a digital map watermark reflecting the accuracy and phase of the digital map.

As shown in FIG. 2, a watermark and an original numeric map are input to a watermark inserter to insert a numerical map watermark to generate a numerical map having a watermark embedded therein. In order to correct the accuracy and phase of the generated watermarked numerical map, the buffered original digital map and the watermarked digital map are compared according to the range of tolerance for each digital map scale. If data exist outside the tolerance range, the digital map data is corrected within the tolerance range. The extracted watermark is terminated when the inserted watermark is extracted through the digital map watermark extractor. If the inserted watermark is not extracted, the digital map watermark insertion process and the digital map correction process are repeated.

3 is a schematic diagram illustrating a method of finding an area deviating from an error range of a digital map having a watermark embedded therein. A buffer zone (area) of X width is created based on the original digital map, and the digital map inserted with a watermark is a target to be corrected when it is out of the buffer zone.

4 is a schematic diagram of contents buffered by an original digital map, a watermarked digital map, and a watermarked digital map. Fig. 4 (a) shows the original numerical map, and (b) shows the watermark with the watermark inserted. (c) The figure shows that the numerical map with the watermark embedded within the tolerance range is processed by buffering the error range value in the original digital map.

FIG. 5 is a schematic diagram illustrating a method of correcting vertex coordinates out of a tolerance range of a digital map by a watermarking algorithm (using a changed coordinate value) in which a watermark is inserted using valid values of vertex coordinate values. Fig. 5A shows that when the watermark is inserted into the coordinate values from Vertex (a) to Vertex (h), the coordinate values of the Vertex (c) are outside the numerical map error tolerance range. (B) The figure shows the figure which corrected the Vertex (c) coordinate value which is out of the tolerance range of digital map to the tolerance range of digital map.

6 is a schematic diagram showing the correction of the vertex coordinates outside the tolerance range of the digital map in a watermark algorithm (using additional coordinate values, angles, etc.) for inserting a watermark by adding a vertex between the vertex and the vertex. Figure 6A shows the coordinate values of Vertex (b ') when watermark is inserted by adding Vertex (a') to Vertex (c ') in the middle of coordinate values from Vertex (a) to Vertex (d). This figure also shows that the tolerance is out of tolerance. Figure (b) shows the figure corrected by the Vertex (b ') coordinate value numerical map error tolerance that is out of the tolerance range.

Claims

A numerical map watermark inserter for inserting a watermark in the numerical map;
A digital map corrector for correcting digital map errors;
A digital map watermark extractor for extracting a watermark from the digital watermark map; And
A watermark verifier for verifying the extracted watermark,
After the buffering process based on the numerical map before the watermark is inserted, it is determined that the numerical map does not exist in the tolerance range after the watermark is inserted, and if it is out of the tolerance range, the numerical map is corrected so as not to fall out of the tolerance range. Digital watermarking device.