Browsing by Author "Lee, Ya-Lin"

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A New Data Hiding Method via Revision History Records on Collaborative Writing Platforms
(2014-02-01)
Lee, Ya-Lin
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Tsai, Wen-Hsiang
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資訊工程學系
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Department of Computer Science
A new data hiding method via collaboratively-written articles with forged revision history records on collaborative writing platforms is proposed. The hidden message is camouflaged as a stego-document consisting of a stego-article and a revision history created through a simulated process of collaborative writing. The revisions are forged using a database constructed by mining word sequences used in real cases from an English Wikipedia XML dump. Four characteristics of article revisions are identified and utilized to embed secret messages, including the author of each revision, the number of corrected word sequences, the content of the corrected word sequences, and the word sequences replacing the corrected ones. Related problems arising in utilizing these characteristics for data hiding are identified and solved skillfully, resulting in an effective multiway method for hiding secret messages into the revision history. To create more realistic revisions, Huffman coding based on the word sequence frequencies collected from Wikipedia is applied to encode the word sequences. Good experimental results show the feasibility of the proposed method.
A New Data Transfer Method via Signal-Rich-Art Code Images Captured by Mobile Devices
(2015-04-01)
Lee, Ya-Lin
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Tsai, Wen-Hsiang
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資訊工程學系
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Department of Computer Science
A new type of signal-rich-art image for applications of data transfer, called signal-rich-art code image, is proposed. The created code image is visually similar to a preselected target image and, with a given message embedded, achieves the effect of the so-called signal-rich art. With its function similar to that of a QR code, such a type of image is produced by encoding the message into a binary bit stream, representing the bits by binary code patterns of 2 x 2 blocks, and injecting the patterns into the target image by a novel image-block luminance modulation scheme. Each signal-rich-art code image may be printed or displayed and then is recaptured using a mobile-device camera. Skillful techniques for counting the number of pattern blocks and recognition of code patterns are also proposed for message extraction from the recaptured version of the signal-rich-art code image. Good experimental results and a comparison of them with those of an existing alternative method show the feasibility and superiority of the proposed new data transfer method.
A New Secure Image Transmission Technique via Secret-Fragment-Visible Mosaic Images by Nearly Reversible Color Transformations
(2014-04-01)
Lee, Ya-Lin
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Tsai, Wen-Hsiang
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交大名義發表
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National Chiao Tung University
A new secure image transmission technique is proposed, which transforms automatically a given large-volume secret image into a so-called secret-fragment-visible mosaic image of the same size. The mosaic image, which looks similar to an arbitrarily selected target image and may be used as a camouflage of the secret image, is yielded by dividing the secret image into fragments and transforming their color characteristics to be those of the corresponding blocks of the target image. Skillful techniques are designed to conduct the color transformation process so that the secret image may be recovered nearly losslessly. A scheme of handling the overflows/underflows in the converted pixels' color values by recording the color differences in the untransformed color space is also proposed. The information required for recovering the secret image is embedded into the created mosaic image by a lossless data hiding scheme using a key. Good experimental results show the feasibility of the proposed method.
Reversible Data Hiding by Image Encryptions and Spatial Correlation Comparisons
(2015-01-01)
Lee, Ya-Lin
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Tsai, Wen-Hsiang
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資訊工程學系
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Department of Computer Science
A reversible data hiding scheme based on double image encryptions and spatial correlation comparisons is proposed, which improves the performance of two previous methods when dealing with flat cover images. A grayscale cover image is first encrypted. The four LSBs of each block pixel in the resulting encrypted image are encrypted once more to embed a message bit, thereby solving the problem of being unable to handle flat images encountered by the previous methods which flip three LSBs of each involved pixel at this stage. Data extraction and image recovery are achieved by a scheme of checking gray-value differences between blocks, which utilizes spatial correlations existing in nature images. Moreover, a side-match scheme that makes use of the spatial correlations of both recovered and unrecovered blocks is proposed to decrease the bit extraction error rate, in contrast with the two previous methods that consider only recovered blocks. Experimental results showing the feasibility of the proposed method are also included.
SIGNAL RICH ART IMAGE - A NEW TOOL FOR AUTOMATIC IDENTIFICATION AND DATA CAPTURE APPLICATIONS USING MOBILE PHONES
(2013)
Lee, Ya-Lin
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Tsai, Wen-Hsiang
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資訊工程學系
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Department of Computer Science
A new tool, called signal-rich-art image, for automatic identification and data capture applications is proposed, which is created from an artistic target image for use as a carrier of a given message. The created image is visually similar to the target image, achieving the effect of so-called signal rich art. With its function similar to those of barcodes or QR codes, such a type of image is produced by fragmenting the composing characters of the message and injecting them into the target image by a novel image-block luminance modulation scheme. Skillful techniques are also proposed for message extraction from a mobile phone-captured version of the signal-rich-art image printed on paper or displayed on a screen. Good experimental results show the feasibility of the proposed method.