| 摘要 |
Data compression apparatus in which input data is compressed according to a target output data quantity using a stage of data quantization, the apparatus comprises: one or more trial quantizers for selecting a degree of quantization so that the target output data quantity is not exceeded; a data selector for selecting a subset of the current data to be quantized; a data store for storing the subset of data; a backsearch quantizer and dequantizer for sequentially quantizing and dequantizing the subset of data at a plurality of degrees of quantization including the degree of quantization selected by the trial quantizer(s) and one or more harsher degrees of quantization; a comparator for comparing data quantized and dequantized by the backsearch quantizer with the stored subset of data, to detect errors introduced by the quantization and dequantization by the backsearch quantizer; and a quantization selector for selecting a final degree of quantization for use in compression of the current data, the final degree of quantization being that degree detected by the comparator to introduce the fewest errors during quantization and dequantization of the subset of data by the backsearch quantizer.
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