Apparatus and method for conversion into a transformed representation or for inverse conversion of the transformed representation

US8195730B2 · kind B2 · utility

Assignee

• Fraunhofer-Gesellschaft zur förderung der angewandten Forschung e.V. · DE

Inventors

• Ralf Geiger · Erlangen, DE
• Gerald Schuller · Erfurt, DE
• Thomas Sporer · Ergolding, DE

Key dates

• Filing date: Jan 13, 2006
• Grant date: Jun 5, 2012
• Expiry date: Apr 18, 2030

Classification

• Technology area (CPC G): Physics
• CPC primary: G10L19/0017
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

For converting first and second blocks of discrete values into a transformed representation, the first block is transformed according to a first transformation rule and then rounded. Then, the rounded transformed values are summed with the second block of original discrete values, to then process the summation result according to a second transformation rule. The output values of the transformation via the second transformation rule are again rounded and then subtracted from the original discrete values of the first block of discrete values to obtain a block of integer output values of the transformed representation. By this multi-dimensional lifting scheme, a lossless integer transformation is obtained, which can be reversed by applying the same transformation rule, but with different signs in summation and subtraction, respectively, so that an inverse integer transformation can also be obtained. Compared to a separation of a transformation in rotations, on the one hand, a significantly reduced computing complexity is achieved and, on the other hand, an accumulation of approximation errors is prevented.