Japan Science and Technology Agency

Kazuo Toraichi

Yasuo Morooka

Kouji Nakamura

Kazuki Katagishi

Shuji Kawasaki

Mitsuteru Nakamura

Masakazu Higuchi

Mitsuaki Nakamura

Jia Lee

Yasuhiro Ohmiya

Tomoyuki Takahashi

Tohru Kawabe

Jonah Gamba

Dean Wu

Provided is an FIR filter capable of obtaining predetermined characteristics with a small number of input taps, delay circuits, and multipliers and achieving an improved response and low cost. In a low-pass filter, a band-pass filter, and a high-pass filter based on an FIR filter, a basic filter is configured that gives a basic impulse response function and has a filter coefficient determined from the impulse response function. Filters having different frequency characteristics are configured by changing the time scale or frequency scale of the basic filter. These filters having different frequency characteristics are combined in a cascade form or a step form, thereby constructing an FIR filter having a small number of taps.

Filter

When encoding an audio signal, it is possible to efficiently encode the audio signal while maintaining high register signal components, and prevent deterioration of sound quality of decoded signal. A digital audio signal is divided into a plurality of frequency bands. The digital audio signal having been divided into each band is function-approximated for each divided band. Further, parameters of function having been function-approximated are encoded. When performing decoding process, parameters of the function of each band are used to perform function interpolation, synthesize the function-interpolated signal of each band interpolated, and decode the signal. Thus, when function-approximating each band, by suitably setting the function equation, it is possible to perform an encoding process while maintaining the high register components and perform a compression-coding process which enables reproduction with very good sound quality.

Audio signal compression and decoding using band division and polynomial approximation

There is provided a sound processing apparatus and a sound processing method which are capable of reproducing discrete data with a high-quality sound matching users' preferences. In a sound processing means, since an interpolation value reflecting a value of a variable parameter &#x3b1; by which the value of a control sampling function c(t) is multiplied can be calculated, an analog signal obtained through the interpolation performed in a sampling function s(t) can be regulated in accordance with the variable parameter &#x3b1; by changing the value of the variable parameter &#x3b1;. In this way, by allowing the user to appropriately change the variable parameter &#x3b1; in accordance with various conditions including music reproduction environments, sound sources, musical tones and so on, it becomes possible to reproduce high-quality-sound music in which its frequency characteristics of the analog signal have changed and a high quality desired by the user is obtained.

Sound processing apparatus and sound processing method

It is possible to provide an image processing device, a method, and a program which can prevent image degradation which occurs when modifying the image magnification. The image processing device includes: an image input unit () which performs an image input; an edge direction calculation unit () which detects the edge direction contained in an image inputted by the image input unit (); and an interpolation position decision unit (), an interpolation object pixel decision unit (), a first direction interpolation unit (), and a second direction interpolation unit () which perform an interpolation process in the edge direction detected by the edge direction calculation unit () on the image inputted by the image input unit ().

Image processing device, method, and program

A signal processing device and a signal processing method are provided which can reproduce a smooth signal in the reproduction of a discrete signal having a non-uniform sample point interval. The device includes a coefficient calculation unitthat inputs a sample point signal Erepresentative of the time of a sample point of a discrete signal Ehaving a non-uniform sample point interval to obtain a coefficient of a sampling function corresponding to the discrete signal, and a reproduction signal calculation unitthat obtains a continuous reproduction signal Eby calculating and outputting a function value within the sample point interval from the discrete signal and the value of the coefficient outputted by the coefficient calculation unit.

Discrete signal processing device and processing method

A signal processing device which outputs a discrete signal composed of a string of the sampling values and parameters m signal. The signal processing device includes a sampling circuit which samples an input signal and outputs a discrete signal, multiple function generators which generate multiple sampling functions with parameters m different from each other, plural inner product operating units for each of parameters m that take an inner product between the input signal and each of plural sampling functions and output an inner product operating value, and a judging unit which determines parameter m providing a minimum error out of multiple errors composed of differences between the sampling value and inner product operating values output from the multiple inner product operating units and outputs the parameters m signal.

Signal processing device and method, signal processing program, and recording medium where the program is recorded

A signal processing device which outputs a discrete signal composed of a string of the sampling values and parameters m signal. The signal processing device includes a sampling circuit which samples an input signal and outputs a discrete signal, multiple function generators which generate multiple sampling functions with parameters m different from each other, plural inner product operating units for each of parameters m that take an inner product between the input signal and each of plural sampling functions and output an inner product operating value, and a judging unit which determines parameter m providing a minimum error out of multiple errors composed of differences between the sampling value and inner product operating values output from the multiple inner product operating units and outputs the parameters.

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Tsukuba, Japan

Kazuo Toraichi