Method and system for data compression

1. A method for data compression, comprising:

obtaining scanning data to be compressed;

compressing the scanning data using a first compression method and a second compression method to obtain a first compressed data and a second compressed data respectively, where a compression ratio of the first compressed data is lower than a compression ratio of the second compressed data; and

determining whether the compression ratio of the first compressed data meets a predetermined compression ratio requirement, if yes, determining the first compressed data as a compression result data corresponding to the scanning data, if no, determining the second compressed data as a compression result data corresponding to the scanning data,

wherein compressing the scanning data using a first compression method comprises:

performing a channel combination on each data of the scanning data along a channel direction according to a combination parameter which does not affect a center scanning area of the scanning data, so as to obtain data after channel combination;

performing a difference calculation on the data after channel combination, so as to obtain a result of difference calculation; and

performing a lossless coding on the result of difference calculation to obtain the first compressed data.

2. The method according to claim 1 , further comprising: outputting the compression result data corresponding to the scanning data.

3. The method according to claim 1 , wherein performing a channel combination along a channel direction according to a combination parameter which does not affect a center scanning area of the scanning data comprises:

selecting, with reference to the combination parameter which does not affect the center scanning area of the scanning data, a predetermined number of channels from both sides of each layer of the scanning data respectively; and

combining data of the selected channels.

4. The method according to claim 1 , wherein performing a difference calculation on the data after channel combination comprises:

performing a difference calculation on the data after channel combination along a layer direction, so as to obtain layer difference data; and

performing a difference calculation on the layer difference data along the channel direction to obtain a target difference data.

5. The method according to claim 4 , wherein performing a lossless coding on the result of difference calculation to obtain a first compression data comprises: performing a lossless coding on the target difference data with symbol bits having a first fixed length, length flag bits having a second fixed length, and data bits having a variable length.

6. The method according to claim 1 , wherein compressing the scanning data using a second compression method comprises: combining the scanning data along two directions of a layer direction and a channel direction according to a target compression ratio, so as to obtain the second compressed data.

7. The method according to claim 6 , wherein combining the scanning data along two directions of a layer direction and a channel direction according to a target compression ratio comprises:

selecting a predetermined number of channels from both sides of each layer of the scanning data according to a target compression ratio;

performing a channel combination on data of the selected channels, so as to obtain scanning data after channel combination; and

combining the scanning data after channel combination along the layer direction.

8. A method for data compression, comprising:

obtaining scanning data to be compressed;

compressing the scanning data using a first compression method to obtain a first compressed data, where compressing the scanning data using the first compression method comprises: performing a channel combination on each data of the scanning data along a channel direction according to a combination parameter which does not affect a center scanning area of the scanning data, so as to obtain data after channel combination, performing a difference calculation on the data after channel combination, so as to obtain a result of difference calculation; and performing a lossless coding on the result of difference calculation to obtain the first compressed data; and

determining the first compressed data as a compression result data corresponding to the scanning data.

9. A system for data compression, comprising: one or more processors configured to:

obtain scanning data to be compressed;

compress the scanning data using a first compression method to obtain a first compressed data;

compress the scanning data using a second compression method to obtain a second compressed data;

determine whether the compression ratio of the first compressed data meets a predetermined compression ratio requirement;

if the compression ratio of the first compressed data meets a predetermined compression ratio requirement, determine the first compressed data as a compression result data corresponding to the scanning data; and

if the compression ratio of the first compressed data doesn't meet the predetermined compression ratio requirement, determine the second compressed data as a compression result data corresponding to the scanning data,

wherein, in a process for compressing the scanning data using a first compression method to obtain a first compressed data, the one or more processors are further configured to:

perform a channel combination on each data of the scanning data along a channel direction according to a combination parameter which does not affect a center scanning area of the scanning data, so as to obtain data after channel combination;

perform a difference calculation on the data after channel combination, so as to obtain a result of difference calculation; and

perform a lossless coding on the result of difference calculation to obtain the first compressed data.

10. The system according to claim 9 , wherein the one or more processors are further configured to: output the compression result data corresponding to the scanning data.

11. The system according to claim 9 , wherein the one or more processors are further configured to:

select, with reference to the combination parameter which does not affect the center scanning area of the scanning data, a predetermined number of channels from both sides of each layer of the scanning data respectively; and

combine data of the selected channels.

12. The system according to claim 9 , wherein the one or more processors are further configured to:

perform a difference calculation on the data after channel combination along a layer direction, so as to obtain layer difference data; and

perform a difference calculation on the layer difference data along the channel direction to obtain a target difference data.

13. The system according to claim 12 , wherein the one or more processors are further configured to perform a lossless coding on the target difference data with symbol bits having a first fixed length, length flag bits having a second fixed length, and data bits having a variable length.

14. The system according to claim 9 , wherein the one or more processors are further configured to combine the scanning data along two directions of a layer direction and a channel direction according to a target compression ratio, so as to obtain the second compressed data.

15. The system according to claim 14 , wherein the one or more processors are further configured to:

select a predetermined number of channels from both sides of each layer of the scanning data according to a target compression ratio;

perform a channel combination on data of the selected channels, so as to obtain scanning data after channel combination; and

combine the scanning data after channel combination along the layer direction.