Topic
Index mapping
About: Index mapping is a research topic. Over the lifetime, 93 publications have been published within this topic receiving 678 citations.
Papers published on a yearly basis
Papers
TL;DR: A “prime factor” Fast Fourier Transform algorithm is described which is self-sorting and computes the transform in place and it is obtained that the required indexing is actually simpler than that for a conventional FFT.
91 citations
TL;DR: A novel reversible data-hiding scheme in the index tables of the vector quantization (VQ) compressed images based on index mapping mechanism that ensures the correctness of secret data extraction and the lossless recovery of index table.
62 citations
Journal Article•
TL;DR: It is found that odd-length type-II and type-III DCTs can be transformed, by means of an index mapping, to a real-valued DFT of the same length using permutations and sign changes only.
Abstract: Efficient methods for mapping odd-length type-II, type-II, and type-IV DCTS to a real-valued DFT are presented. It is found that odd-length type-II and type-III DCTs can be transformed, by means of an index mapping, to a real-valued DFT of the same length using permutations and sign changes only. The real-valued DFT can then be computed by efficient real-valued FFT algorithms such as the prime factor algorithm. Similar mapping is introduced to convert a type-IV DCT to a real-valued DFT up to a scaling factor and some additions. Methods for computing DCTs with even lengths are also discussed. >
57 citations
TL;DR: Based on the equations obtained from the derivation, input and output index mappings are introduced in the form of tables that enables any prime-factor-decomposable discrete cosine transform (DCT) to be implemented in a straight-forward manner.
Abstract: A formal direct derivation of the prime-factor-decomposed computation algorithm is presented. The derivation is direct in the sense that it is based on the real cosine function without resort to the discrete Fourier transform expressions or the complex functions. Based on the equations obtained from the derivation, input and output index mappings are introduced in the form of tables. This tabulation enables any prime-factor-decomposable discrete cosine transform (DCT) to be implemented in a straight-forward manner. The use of the index mapping tables is demonstrated for the 12-point DCT. >
46 citations
27 Apr 1993
TL;DR: The input index mapping adopted is the Ruritanian mapping; the output index mapping is the same as B.G. Lee's (IEEE Trans. ASSP.37, no.2, p.237-44, Feb. 1989).
Abstract: The input index mapping adopted is the Ruritanian mapping; the output index mapping is the same as B.G. Lee's (IEEE Trans. vol. ASSP.37, no.2, p.237-44, Feb. 1989). Hardware implementations for the prime-factor DCT are also studied. The methodology, which deals with general (N/sub 1/*N/sub 2/)-point DCTs, where N/sub 1/ and N/sub 2/ are mutually prime, is illustrated by converting a 15-point DCT problem into a (3*5)-point 2-D DCT problem. >
24 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 2 |
| 2020 | 4 |
| 2019 | 4 |
| 2018 | 4 |
| 2017 | 5 |
| 2016 | 6 |