Lossless compression of fragmented image data
Lossless compression of fragmented image data is disclosed. In some embodiments, a stream of information is received, wherein the stream of information comprises a sequence of tuples and wherein each of the tuples comprises data elements corresponding to one of a plurality of input channels. A channel transformer is employed to rearrange the data elements into a plurality of output channels for an output stream wherein the output channels have higher compressibility than the input channels. The compressed output stream is stored.
1. A system, comprising:
a processor configured to:
receive an input sequence of data comprising a first channel;
generate a second channel based at least in part on a transform of data of the first channel;
generate a compressed output by encoding the second channel with a variable length code adapted to statistics of the data elements of the second channel, wherein the compressed output is based on a selection of one or more thresholds according to data elements of the second channel, and the one or more thresholds are selected based at least in part on a distribution of values corresponding to the data elements of the second channel and a frequency of values corresponding to the data elements of the second channel; and
a memory that stores the compressed output.
2. The system of claim 1 , wherein generating the second channel comprises performing a plurality of transforms including a differential transform.
3. The system of claim 1 , wherein the transform on the data of the first channel reduces or eliminates a redundancy of the data of the first channel.
4. The system of claim 1 , wherein the transform on the data of the first channel uses a continuity of data of the first channel.
5. The system of claim 1 , wherein the transform on the data of the first channel exploits continuity properties within the first channel and wherein the second channel is more compressible than the first channel.
6. The system of claim 1 , wherein the transform on the data of the first channel is selected based at least in part on a compressibility of data resulting from the transform.
7. The system of claim 1 , wherein the input sequence is associated with a fragment of an image.
8. The system of claim 7 , wherein the fragment is independently compressed and decompressed without reference to other fragments of the image.
9. The system of claim 7 , wherein the transform of data of the first channel is a different transform, and the transform of the data of the first channel is applied for every pixel independently.
10. The system of claim 1 , wherein the transform corresponds to a differential transform, and wherein first data elements of the second channel and the first channel are the same and wherein the remaining data elements of the second channel comprise differences between consecutive data elements of the first channel.
11. The system of claim 1 , wherein the compressed output comprises a lossless compression of the input sequence.
12. The system of claim 1 , wherein the selection of one or more thresholds are selected by performing a threshold selection process.
13. A method, comprising:
receiving, by one or more processors, an input sequence of data comprising a first channel;
generating, by one or more processors, a second channel based at least in part on a transform of data of the first channel;
generating, by one or more processors, a compressed output by encoding the second channel with a variable length code adapted to statistics of the data elements of second channel, wherein the compressed output is based on a selection of one or more thresholds according to data elements of the second channel, and the one or more thresholds are selected based at least in part on a distribution of values corresponding to the data elements of the second channel and a frequency of values corresponding to the data elements of the second channel; and
storing the compressed output.
14. The method of claim 13 , wherein generating the second channel comprises performing a plurality of transforms including the differential transform.
15. The method of claim 13 , wherein the transform on the data of the first channel exploits continuity properties within the first channel and wherein the second channel is more compressible than the first channel.
16. The method of claim 13 , wherein the transform on the data of the first channel is selected based at least in part on a compressibility of data resulting from the transform.
17. The method of claim 13 , wherein the transform of data of the first channel is a different transform, and the transform of the data of the first channel is applied on a pixel-by-pixel basis.
18. A computer program product embodied in a non-transitory computer readable storage medium and comprising computer instructions for:
receiving an input sequence if data comprising a first channel;
generating a second channel based at least in part on a transform of data of the first channel;
generating a compressed output by encoding the second channel with a variable length code adapted to statistics of data elements of the second channel, wherein the compressed output is based at least in part on a selection of one or more thresholds according to the data elements of the second channel, and the one or more thresholds are selected based at least in part on a distribution of values corresponding to the data elements of the second channel and a frequency of values corresponding to the data elements of the second channel; and
storing the compressed output.
19. The system of claim 1 , wherein the second data is better compressible than the first channel.
20. The system of claim 1 , wherein the processor is further configured to select a transform with which the data of the first channel is to be transformed, wherein the transform is selected based at least in part on an estimation of a compressibility of a new channel obtained by transforming the first channel.
21. The system of claim 1 ,
wherein the one or more threshold are selected based at least in part on using at least a sequence of values corresponding to the second channel, a depth, and a frequency threshold.
22. A method, comprising
receiving, by one or more processors, an input sequence of data comprising a first channel;
generating, by one or more processors, a second channel based at least in part on a transform of data of the first channel;
generating, by one or more processors, a compressed output by encoding the second channel with a variable length code adapted to statistics of the data elements of second channel, wherein the compressed output is based on a selection of one or more thresholds according to data elements of the second channel, and the one or more thresholds are selected based at least in part on using at least a sequence of values corresponding to the second channel, a depth, and a frequency threshold; and
storing, by one or more processors, the compressed output.