QR code watermark image data compression and coding method

Abstract

The invention discloses a QR code watermark image data compression and coding method, and the method comprises the steps: carrying out the decomposition of a QR watermark image through combining with the symbol structure features of a QR code after DWT transformation and compression, and extracting data and an error correcting code part therein; rearranging the data and an error correcting code in a one-dimensional binary watermark information sequence, and hen carrying out the compression and coding of the watermark information sequence through employing an improved jump block coding mechanism; finally enabling a binary sequence generated after compression and coding to serve as the watermark information embedding carrier data. The method employs the coding mechanism and structure features of the QR code to solve a problem of data compression of a QR code watermark image. The method gives the play to the strong capability of error correction of the QR code, employs the lossless coding and loss coding mechanisms in the compression and coding process, reduces the data size, and also guarantees that a compressed code can be normally decoded and recognized. After compression and coding, the binary sequence, compared with an original QR code watermark image, is higher in data compression ratio, and can meet the requirements of a small-data-size watermark information carrier for the size of embedded data.

Description

technical field [0001] The invention belongs to the field of geospatial data information security protection, and in particular relates to a QR code watermark image data compression and encoding method aimed at a watermark information carrier with a small amount of data. Background technique [0002] Tile remote sensing image data and tile raster map data are important data sources of the geographic information public service platform represented by "Tianditu". With the popularization of network geographic data services, tile data sources are abundant and easy to download. The security problems caused by illegal use and profit-making are becoming more and more prominent, which directly affects the rights and interests of data owners and the enthusiasm for sharing. It is urgent to introduce scientific and effective technical means to solve the information security problems of tile data. [0003] Digital watermarking technology is an emerging and cutting-edge information secur...

AI Technical Summary

Problems solved by technology

[0005] Tile data has the distinct characteristics of constant size and small amount of single data, which determines that the digital watermarking algorithm applied to tile data must strictly control the amount of embedded data to adapt to the information carrying capacity of the carrier data; however, the small amount of embedded data Equivalent to a shorter watermark information sequence, it will be difficult to characterize and verify the copyright ownership of data products

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