著者

Saho YAGYU Akie SAKIYAMA Yuichi TANAKA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)

巻号頁・発行日

vol.E99-A, no.9, pp.1646-1654, 2016-09-01

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We propose an edge-preserving multiscale image decomposition method using filters for non-equispaced signals. It is inspired by the domain transform, which is a high-speed edge-preserving smoothing method, and it can be used in many image processing applications. One of the disadvantages of the domain transform is sensitivity to noise. Even though the proposed method is based on non-equispaced filters similar to the domain transform, it is robust to noise since it employs a multiscale decomposition. It uses the Laplacian pyramid scheme to decompose an input signal into the piecewise-smooth components and detail components. We design the filters by using an optimization based on edge-preserving smoothing with a conversion of signal distances and filters taking into account the distances between signal intervals. In addition, we also propose construction methods of filters for non-equispaced signals by using arbitrary continuous filters or graph spectral filters in order that various filters can be accommodated by the proposed method. As expected, we find that, similar to state-of-the-art edge-preserving smoothing techniques, including the domain transform, our approach can be used in many applications. We evaluated its effectiveness in edge-preserving smoothing of noise-free and noisy images, detail enhancement, pencil drawing, and stylization.

著者

Masaki ONUKI Yuichi TANAKA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)

巻号頁・発行日

vol.E97-A, no.9, pp.1907-1917, 2014-09-01

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Decimation and interpolation methods are utilized in image coding for low bit rate image coding. However, the decimation filter (prefilter) and the interpolation filter (postfilter) are irreversible with each other since the prefilter is a wide matrix (a matrix whose number of columns are larger than that of rows) and the postfilter is a tall one (a matrix whose number of rows are larger than that of columns). There will be some distortions in the reconstructed image even without any compression. The method of interpolation-dependent image downsampling (IDID) was used to tackle the problem of producing optimized downsampling images, which led to the optimized prefilter of a given postfilter. We propose integrating the IDID with time-domain lapped transforms (TDLTs) to improve image coding performance.

著者

Haruna KAMOCHI Gen KUSAKA Mami ISHIKAWA Sane ISHIKAWA Yuichi TANAKA

出版者

The Japan Neurosurgical Society

雑誌

Neurologia medico-chirurgica (ISSN:04708105)

巻号頁・発行日

vol.53, no.4, pp.217-220, 2013 (Released:2013-04-25)

参考文献数

15

被引用文献数

6 8

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Late onset cerebrospinal fluid (CSF) leakage, such as rhinorrhea or otorrhea, is a rare complication of closed head injury. We encountered two cases of delayed CSF leakage more than 10 years after head injury. In both cases, surgical treatments were performed using intradural approaches, and the dural defects were closed with viable pedicled flaps. After surgery, the CSF leakage was completely cured and no remarkable complication was observed in either case. The present two cases of late onset CSF leakage suggest that surgical repair procedures should be performed as soon as the leaks are discovered. A bifrontal intracranial approach is recommended to treat frontal cranial base leakage. Temporal craniotomy is recommended to treat temporal base leakage. All cases should be treated using an intradural approach, and the dural defect is best repaired with viable pedicled flaps.