A method for encoding and decoding a javascript object notation (JSON) document utilizing a statistical tree representing a JSON Schema. The encoded statistical tree may be optimized.

[Problem] To suppress increases in the size of a fully indexable dictionary while making it possible for a target bit stream to be subjected to two types of selection operation employing the fully indexable dictionary.

[Solution] An information processing device (100) is provided with a storage unit (10) which stores a data structure (11) used to represent a bit stream formed using a first value and a second value. The data structure (11) includes: first data specifying the positions on the bit stream of all or some succession segments including a succession of one or more of the first value or the second value; second data specifying, for some of the succession segments, the number of first values that have appeared on the bit stream from the beginning of the bit stream as far as the succession segment; and third data specifying, for some of the succession segments, the number of second values that have appeared on the bit stream from the beginning of the bit stream as far as the succession segment.

In an approach to analyzing a path on a graph, a computer receives a graph comprising a plurality of vertices and edges, each edge linking two vertices. The computer, for each one of said plurality of vertices, analyzes edges linked to said one of plurality of vertices to determine a number of outbound links from said one of plurality of vertices, orders said edges, and assigns a value to each ordered edge. The computer, for the graph, receives a path comprising a plurality of edges linking two of said plurality of vertices through at least one other of said plurality of vertices, encodes said path, the encoding using said number of outbound links and said assigned values of each of said one or more edges linking said two of said plurality of vertices, compresses the encoded path, and analyzes said path on said graph using said compressed, encoded path.

In an approach to analyzing a path on a graph, a computer receives a graph comprising a plurality of vertices and edges, each edge linking two vertices. The computer, for each one of said plurality of vertices, analyzes edges linked to said one of plurality of vertices to determine a number of outbound links from said one of plurality of vertices, orders said edges, and assigns a value to each ordered edge. The computer, for the graph, receives a path comprising a plurality of edges linking two of said plurality of vertices through at least one other of said plurality of vertices, encodes said path, the encoding using said number of outbound links and said assigned values of each of said one or more edges linking said two of said plurality of vertices, compresses the encoded path, and analyzes said path on said graph using said compressed, encoded path.

A computer-readable recording medium stores a program causing a computer to determine the size of an applied 2.sup.N-branch non-contact Huffman tree depending on where in a range the total number of types (X) of character information groups exists. The size of the 2.sup.N-branch non-contact Huffman tree has the maximum number of branches, 2.sup.N. The radicand N is an upper limit of the length of a compression code. Thus, when the size of the 2.sup.N-branch non-contact Huffman tree is determined, the radicand (N) may be determined depending on the total number of types (X) of character information groups. Specifically, when the total number of types (X) of character information groups is 2.sup.x2<X2.sup.x1, if the maximum number of branches (2.sup.N) is at least 2.sup.x1, a Huffman tree can be established. To minimize the size, N=x1 may be adopted. Further, when the total number of types (X) of character information groups is 2.sup.x1<X2.sup.x, if the maximum number of branches (2.sup.N) is at least 2.sup.x, a Huffman tree can be established. To minimize the size, N=x may be adopted.

Compressing files is disclosed. An input file to be compressed is first aligned. Aligning the file includes splitting the file into sequences that can be aligned. The result is a compression matrix, where each row of the matrix corresponds to part of the file. The compression matrix may also serve as a warm start if additional compression is desired. Compression may be performed in stages, where an initial compression matrix is generated in a first stage using larger letter sizes for alignment and then a second compression stage is performed using smaller letter sizes. A consensus sequence id determined from the compression matrix. Using the consensus sequence, pointer pairs are generated. Each pointer pair identifies a subsequence of the consensus matrix. The compressed file includes the pointer pairs and the consensus sequence.

A method for compressing RDF tuples. The method including obtaining RDF tuples, obtaining a dictionary of indices, encoding for each RDF tuple the indices attributed to the subject and the object, grouping RDF tuples sharing the same predicate and for each group sorting the RDF tuples by considering the encoding of the subject and the object, and for each group of sorted RDF tuples, serializing the index of the shared predicate, serializing the encoding of the subject and the object of a first RDF tuple, and for each RDF tuple of the group of sorted RDF tuples subsequent to the first RDF tuple of the group, computing a difference between the encoding of the subject and the object of a current RDF tuple and the encoding of the subject and the object of a previous RDF tuple, and serializing the computed difference in a form of a variable-length integer.

A method produces a compressed sequence of events stored in a memory, originating from an event-based camera, the sequence comprising a first run-length code representing timestamps of the sequence of events; and subsequent compressed codes including one of: (i) a second run-length code representing first coordinates of the sequence of events, at least one dictionary code representing second coordinates of the sequence of events, and data representing polarities of the sequence of events; (ii) a second run-length code representing first coordinates of the sequence of events, a number of bit-packed fields, each representing a second coordinate and polarity pair of the sequence of events; or (iii) a number of bit-packed fields, each representing a first and second coordinate and polarity triplet of the sequence of events.