Method and system for error resilient compression and decompression of computed tomography data

摘要

A method and system for transferring data from a rotating data source to a stationary target over a slip ring. The system includes a compressor on a rotor, a decompressor on a stationary platform, and respectively corresponding memory buffers. The data is optionally compressed in the event that the slip ring capacity is below the required rate. The compressor a predictor unit, an entropy encoder unit and an error protector unit. The predictor unit may use stored data as reference from a set of frames and locations within them. Encoding of locations may be carried out with a Golomb-Rice encoded integer, and entropy encoding of differences may involve Golomb-Rice encoding with parameter K varying for each group of data units. The error protector protects parameters inserted into data stream with an error protection code while most of the data can remain without protection.

主权项

1. A data-transferring slip ring system comprising:
a data compressor positioned on a rotating platform, the data compressor having input and output and configured to be operably connectable to and to receive data at the input from a data generator, said data compressor including
a predictor unit,an entropy encoder unit, andan error protector unit,wherein said predictor unit, entropy encoder unit, and error protector unit are adapted to be in data-transfer communication with one another; a data decompressor positioned on a stationary platform and configured to be operably connectable to a target; and a slip ring operably connecting and configured to transfer data between the output of said data compressor and said data decompressor, wherein said predictor unit includes means for processing data, received at the input, in groups of data pixels and means for predicting data to be compressed based on
(i) F previously stored data frames and(ii) one or more coordinates of data pixels within said data frames expressed as a coordinate vector V encoded as a positive integer; wherein said entropy encoder unit is adapted to encode the data to be compressed as predicted by the predictor unit; wherein said error protector unit is adapted (i) to embed error-correction code into the encoded data to protect one or more of an encoding parameter Kmin, of the Golomb-Rice encoding for which a minimal encoding size is achieved, an index Fmin of a reference data frame, and a coordinate offset vector Vmin corresponding to said reference frame and (ii) to transfer the data with embedded error-correction code to the output, wherein said predictor unit is adapted to select the best prediction per group of data pixels determined by the index Fmin of a reference data frame and the offset vector Vmin within the reference data frame; and wherein said entropy encoder is adapted to encode the best prediction's location in history and a difference between the prediction and the incoming data using a set of parameters Kmin and P added into the output data stream.