Wyniki wyszukiwania - BazTech

1

A novel tamper detection scheme for BTC-compressed images

Hu Y. C., Chen W. L., Lo C. C., Wu C. M.

Opto-Electronics Review

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2013

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Vol. 21, No. 1

137-146

EN

A novel image authentication scheme for the compressed images of block truncation coding (BTC) is proposed in this paper. In the proposed scheme, 1-bit authentication data is generated from the quantization levels of each image block. Multiple block permutations are generated by using the random sequences induced by the selected random number seeds. Multiple copies of the authenticaiton data are embedded into the bit maps of BTC-compressed image blocks based on the block permutations. Experimental results show that the proposed scheme achieves good detecting accuracy while keeping good image quatiy of the embedded image.

2

Quantizer design for multilevel BTC

Savic M., Peric Z., Panic S.

Przegląd Elektrotechniczny

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2011

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R. 87, nr 12a

153-155

EN

In this paper a novel image compression method based on Block Truncation Coding technique is presented. The essence of this method is the designing of both, fixed and adaptive, multilevel quantizers and their appliance for discrete input. Experimentaly obtained results show that usage of compression based on this method provide lower bit rate values comparing to the previosly BTC-based results, while attaining requested level of quality.

PL

Zapropnowano nową metodę kompresji obrazu bazującą na technice BTC. Ideą tej metody jest zaprojektowanie wielopoziomowych kwantyzerów stałych i adaptacyjnych. Eksperymenty potwierdziły, że uzyskano lepszą przepływność bez pogorszenia jakości.

3

Reversible Steganography for BTC-compressed Images

Chang C-C., Lin C-Y., Fan Y-H.

Fundamenta Informaticae

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2011

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Vol. 109, nr 2

121-134

EN

Reversible steganography becomes a popular hiding problem in recent years. A reversible steganographicmethod can reconstruct an original image without loss from the stego-image after extracting the embedded data. Unlike traditional reversible methods in which data is hidden in uncompressed images, we propose a reversible scheme for BTC (block truncation coding)- compressed images. The secret data embedded in the compressed image are more difficult to detect than in the uncompressed image. To achieve reversibility, the properties of side matching and BTCcompressed code are applied. The experimental results show that the proposed method is feasible for BTC-compressed images and can embed one more bit in each BTC-encoded block.

4

Predictive Grayscale Image Coding Scheme Using VQ and BTC

Hu Y-C.

Fundamenta Informaticae

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2007

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Vol. 78, nr 2

239-255

EN

A predictive image compression scheme that combines the advantages of vector quantization and moment preserving block truncation coding is introduced in this paper. To exploit the similarities among neighboring image blocks, the block prediction technique is employed in this scheme. If a similar compressed image block can be found in the neighborhood of current processing block, it is taken to encode this block. Otherwise, this image block is encoded either by vector quantization or moment preserving block truncation coding. A bit-rate reduced version of the proposed scheme is also introduced. According to the experimental results, it is shown that the proposed scheme provides better image quality at a low bitrate than these comparative schemes.

5

Multiple Images Embedding Scheme Based on Moment Preserving Block Truncation Coding

Hu Y-C.

Fundamenta Informaticae

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2006

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Vol. 73, nr 3

373-387

EN

A low-complexity grayscale image embedding scheme that can embed multiple secret images is proposed in this paper. In this scheme, different users can extract different secret images according to the secret keys they hold. To reduce the storage cost of the secret images, each of the secret images is first compressed using an improved version of the moment preserving block truncation coding scheme. The compressed message of each secret image is then encrypted by the DES cryptography system with different secret key and then embedded into the host image using the modulus least-significant-bit substitution technique. According to the experimental results, it is shown that the proposed scheme consumes a little computational cost. Besides, different users can extract different number of secret images. In other words, the proposed scheme indeed provides a good approach for the hiding of grayscale images with access control.

6

A Novel Color Image Hiding Scheme Using Block Truncation Coding

Hu Y-C., Lin M-H., Jiang J-H.

Fundamenta Informaticae

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2006

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Vol. 70, nr 4

317-331

EN

In this paper, a novel color image hiding scheme that is capable of hiding two color secret images into a color host image is proposed. The secret images to be embedded are first compressed by the single bit map block truncation coding. DES encryption is then conducted on the compressed message before the secret image is embedded into the rightmost 3, 2, 3 bits of the R, G, B channels of every pixel in the host image. The experimental results show that our scheme provides an average secret image quality of 29.220 dB. In addition to the improved quality of both host images and retrieved secret images, our scheme further strengthens the protection of the secret images by conducting image compression and DES encryption on the secret image in advance. Therefore, our scheme not only extends the hiding capability of host images, but also is practical and secure.