Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Sebastian Streich

Markus Kurt Cremer

Claas Derboven

The apparatus for converting an information signal from a time to a variable spectral representation includes a means for windowing the information signal, a means for converting the windowed information signal to a spectral representation, and a means for weighting a set of information signal spectral coefficients with several sets of complex base function coefficients provided from a means for providing the sets of base function coefficients. The sets of base function coefficients are derived from base functions of various frequencies by windowing and transform, wherein several sets of base function coefficients are provided for one and the same base function for base functions of higher frequencies, wherein the windows for providing these sets are related to various time portions of the base function. The variable spectral representation exhibits variable bandwidth of the variable spectral coefficients, which are efficient and accurate to calculate and especially suited for music analysis purposes.

Apparatus and method for converting an information signal to a spectral representation with variable resolution

An apparatus for determining a type of chord has a means for providing a reference vector for the type of chord, a means for providing a reference vector from a test signal, and a means for comparing the reference vector with the test signal vector. The means for providing a reference vector is configured to provide, for the type of chord, a reference vector from a plurality of different reference vectors. In addition, the means for providing a test signal vector from the test signal is configured to provide the test signal vector having a plurality of test signal vector elements. In addition, the means for comparing the reference vector with the test signal vector is configured to compare the reference vector and the test vector or versions of the test signal vector which are cyclically shifted by different shift values, in order to obtain various comparison results which are allocated to the test signal vector or shift values, so as to determine the type of chord on the basis of an extreme comparison result and the shift value associated with same.

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Barcelona, Spain

Sebastian Streich