Masahiro Iwahashi

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While conventional DCT outputs real numbers and it is not suitable for lossless coding of images, the integer DCT (Int-DCT) outputs integer numbers and can serve as a lossless coding and lossy coding compatible to the conventional DCT. Recently, our group has proposed an optimum assignment method of word length of multipliers in the Int-DCT assuming(More)
The combination of a change in lifestyle toward Western habits and an aging society, has led to a steady increase in the incidence of atherosclerotic diseases in the Japanese population. Coronary artery disease (CAD), carotid stenosis (CS), and peripheral artery disease (PAD) are major manifestations of generalized atherosclerosis and increase the risk of(More)
Describes the development of a technique for subband image coding called the symmetric extension method which utilizes the nature of a symmetrically extended image to achieve high quality coding. There are, however, some restrictions on the usable subband coding system. The development is done based on the property of a symmetrically extended signal in the(More)
This paper proposes how to detect water level from a video signal for use of automatic river surveillance. The water level is recognized as a boundary line between the land region and the water region. A conventional method uses a "vertical" edge detector to extract a horizontal line as the running water surface. "Subtraction" of frames is also accompanied(More)
SUMMARY In this paper, we propose a bit-rate adaptive coding system based on lossless DCT (L-DCT). Our adaptive coding system consists of three different operation modes: ÐÓ××¹ ÐÐ××, ÒÒÖ¹ÐÓ××ÐÐ×× and ÐÓ××Ý coding modes. Quantization is applied in transform domain (after the L-DCT) and spatial domain (before the L-DCT) in lossy mode and near-lossless mode,(More)
SUMMARY In this paper, we propose a new one-dimensional (1D) integer discrete cosine transform (Int-DCT) for unified lossless/lossy image compression. The proposed 1D Int-DCT is newly designed to reduce rounding effects by minimizing number of rounding operations. The proposed Int-DCT can be operated not only lossless coding for a high quality decoded image(More)
We evaluated the usefulness of prognostic markers in patients with diffuse large B-cell lymphoma (DLBCL) treated with cyclophosphamide, vincristine, doxorubicin, and prednisolone (CHOP) +/- rituximab (R-CHOP) in Japan. We studied 730 patients with DLBCL; 451 received CHOP and 279 R-CHOP. We analyzed biopsy samples immunohistochemically for markers of(More)
This report proposes a two layer lossless coding system for high dynamic range (HDR) images expressed in a floating point data format. Its encoder outputs compressed image data in two layers. From the base layer, a standard low dynamic range (LDR) image is decoded. Merging with the enhancement layer, the original HDR image is decoded without any loss. We(More)
In this report, we propose a reversible two dimensional (2D) discrete wavelet transform (DWT) compatible to the irreversible 9–7 DWT for lossy coding in the JPEG 2000. All the filters and scalings are factorized into lifting steps, and signals are rounded into integers, so that the proposed DWT becomes reversible and applicable to lossless coding.(More)