Data compression
AssigneeDublin City University
InventorsNoel Brady, Liam Ward, Tommy Curran, Noel Murphy
Life of this patent
Estimating the term…
Abstract
Image data such as binary mask image data is compressed by partitioning the data into blocks. An arithmetic encoder is initiated for each block and terminated at the end of the block. For each block, there is a fixed template/PDF table pair model which is chosen at the beginning of the block according to motion compensation and other inputs. One model has a template with spatially-correlating samples only, the other having both temporally and spatially-correlating samples. Estimations are made for values of samples which border the current block according to simple rules for the particular template.
Claims12
A method of encoding binary image data comprising the steps of:
- receiving the image data;
- determining for each sample a Probability Density Function (PDF) table;
- computing for each sample a context number according to a template;
- selecting for each sample a PDF from the PDF table according to the context number;
- encoding with an arithmetic encoder each sample in turn according to the PDF and the sample value, wherein,
- the received image data is partitioned into discrete blocks, each block comprising a plurality of samples,
- the samples of each block are encoded using a fixed template to compute the context number by assigning an estimated value of the context number calculated from at least one sample in a neighbouring block to at least one sample of the block, and a fixed PDF table.
Dependencies are inferred from the claim text.