Michiharu Niimi

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This paper describes a new technique to embed secret data into a dummy image by using image segmentation based on a local complexity measure. The key idea to this approach is that a binary image can be categorized as “informative” and “noise-like” regions , which are segmented by a “complexity measure.” If the embedding data is noiselike, we can hide it in(More)
This paper presents a steganography method using lossy compressed video which provides a natural way to send a large amount of secret data. The proposed method is based on wavelet compression for video data and bit-plane complexity segmentation (BPCS) steganography. In wavelet-based video compression methods such as 3-D set partitioning in hierarchical(More)
In a highly digitalized world we live today, the data to be transmitted are confidential at times, and in such cases there are many malicious intruders who try to access this information. Steganography is one recent method to provide reliable security. Steganography is the science of embedding data into different covers such that the data embedded is(More)
This paper concerns color image restoration aiming at objective quality improvement of compressed color images in general rather than merely artifact reduction. In compressed color images, colors are usually represented by luminance and chrominance components. Considering characteristics of human vision system, chrominance components are generally(More)
This paper presents a modified QIM-JPEG2000 steganography which improves the previous JPEG2000 steganography using quantization index modulation (QIM). Since after-embedding changes on file size and PSNR by the modified QIM-JPEG2000 are smaller than those by the previous QIM-JPEG2000, the modified QIM-JPEG2000 should be more secure than the previous(More)
This paper presents two JPEG steganographic methods using quantization index modulation (QIM) in the discrete cosine transform (DCT) domain. The two methods approximately preserve the histogram of quantized DCT coefficients, aiming at secure JPEG steganography against histogram-based attacks. In comparison with F5 as a representative JPEG steganography, the(More)
This paper discusses an attack to BPCS-Steganography (Bit-Plane Complexity Segmentation-Steganography) and presents a countermeasure. BPCS is an image-based steganographic method. BPCS embeds secret data by replacing blocks that appear noise-like on bit-planes. Blocks on bit-planes are categorized as a "noise-like region" or an "informative region" by means(More)
BPCS-Steganography is a steganographic method that hides secret messages in digital images. BPCS-Steganography extracts local regions of the image to embed using image segmentation based on a complexity measure that separates the image into “informative” and “noise-like” regions. The human visual system will be unable to perceive any difference by the(More)