Table-based low-level image classification and compression system
US6404923B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 29, 1996 |
| Grant date | Jun 11, 2002 |
| Priority date | — |
| Expiry date | Mar 29, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T9/008
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system for classifying image elements comprising means for converting an image into a series of vectors and a hierarchical lookup table that classifies the vectors. The lookup table implements a pre-computed discrete cosine transform (DCT) to enhance classification accuracy. The hierarchical lookup table includes four stages: three of which constitute a preliminary section; the fourth stage constitutes the final section. Each stage has a respective stage table. The method for designing each stage table comprises a codebook design procedure and a table fill-in procedure. Codebook design for the preliminary stages strives to minimize a classification-sensitive proximity measure; codebook design for the final stage attempts to minimize Bayes risk of misclassification. Table fill-in for the first stage involves generating all possible input combinations, concatenating each possible input combination to define a concatenated vector, applying a DCT to convert the address vector to the spatial frequency domain, finding the closest first-stage codebook vector, and assigning to the address the index associated that codebook vector. Table fill-in for subsequent stages involves decoding eac…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.