JPS63299413A - System for deciding branching direction of binary tree - Google Patents

Abstract

PURPOSE:To shorten a processing time as a whole, by supplying a value based on a distortion measure between reference vectors as a scalar quantity in addition to two reference vectors to decide a direction to be branched to the node of a binary tree, and deciding branch to a reference vector side on one side. CONSTITUTION:Assuming that a leftward reference vector TL is set as TL=14 and a rightward reference vector TR as TR=6, the distortion measure dLR between those reference vectors is expressed as dLR=(TL-TR)<2>=(14-6)=8<2>=64. Therefore, the scalar quantity goes to dLR/4=16. In such a way, it is compared with the dLR/4, and if a condition dL<dLR<4 is satisfied, the branch to the leftward reference vector TL side performed, and it is not required to calculate the distortion measure with the rightward reference vector TR.

Description

[Detailed Description of the Invention] [Technical Field] A matching process that compares an input multidimensional vector with a reference vector is used to classify input multidimensional vectors, or to encode and decode input multidimensional vectors. A selection of approximate reference vectors is performed.

The present invention sequentially and hierarchically configures reference vectors as a binary tree at each node, and successively compares the input vector and the reference vector at these nodes. The present invention relates to a determination method that selects a branch to a vector and repeats this at successive nodes to select an X quasi-vector that is closest to an input vector.

[Prior art]

FIG. 2 shows 23-8 reference vectors 71. ”;' 2
゜F. This shows an example of a binary tree consisting of the reference vectors 〒I
N21. The two reference vectors ``f2 +, L, 〒21.R and the second
The two reference vectors 〒2゜L+"f21R at the node N2LR of the layer are respectively representative, and these reference vectors 〒101."'F I RO values, as will be explained in more detail later, It is common practice to use the average value of the two reference vectors of the above-mentioned cascaded lower nodes.

More specifically, referring to the figure, node N1. .

As the reference vector 〒1L, this node N, 1. Vector of lower nodes N2LL and N2LR cascaded to 〒2
I-5 and 〒25. In addition, as the reference vector 〒IR of node N1R, the average value of 6 vectors 〒2RL and I2RR of the lower nodes N2RL and N2RR cascaded to this node is used, and the second and third layer layer,
Similar reference vectors are used for lower layers such as the third and fourth layers.

Figure 3 conceptually shows the creation of a dictionary by classifying a large number of vectors for performing such binary tree matching.
In other words, the space S in which the dictionary exists is shown by a solid rectangle, and in this example, it is divided into the eight spaces mentioned above so that the same number of these reference vectors are distributed to each space, and each space is divided into the eight spaces. a reference vector E7 + representing this space by, for example, the average value of the vectors to which it belongs;
”;' l+y8 is generated.

And these reference vectors 71, '72. ”
"""" A reference vector that is relatively close to E'8, for example, E
7 + , ”;' 2 is set as a reference vector T
2 L L is created and the above reference vector 73 is created in the same manner.
．． -; Reference vector T created from 21. Let the average value with R be the reference vector 〒1L for the next higher node N1L.

Furthermore, as above, the reference vector V5. A higher-order node No. is generated using the reference vector 〒1R created from V6177 and y8 and the above-mentioned reference vector 〒1L.

In conventional binary tree matching for multidimensional vectors, in order to perform branching at each node generated in this way, at each node there is a In this method, distortion calculations for multidimensional vectors must be performed twice, and as the vector becomes more dimensional, the time required for this distortion calculation increases, resulting in an increase in overall processing time.

〔the purpose〕

An object of the present invention is to quickly determine branches when matching a reference vector and an input vector configured as a hierarchical binary tree at each node.

〔composition〕

The present invention will be described below based on one embodiment regarding branch determination at one node.

Each element of the dimensional vector zo is input as 71 (i.e., Ma, , Ma, Ma,), and one of the dimensional vectors 〒R1〒L is used as the two criteria for branching left or right at this node T. Let each element of the vector 〒 be r + , T: 2. --- t' y,
If the square strain of the difference between the elements of each vector is used as the strain temperature d, it is expressed as follows.

Using such a strain temperature, the strain temperature dL between the dimensional vector zo and the reference vector 〒L for branching to the left can be calculated manually.
is dL-(mer, rLt)-
--(2), and the strain temperature dL between the reference vector 〒 and the necessary reference vector 〒, which is required to manually branch into the dimensional vector calculation direction, is
aR= (ball°1.j″Rt)
It is expressed as (3).

Similarly, the strain temperature dRL between these left and right reference vectors is d L R-(TLl, 'E"Rj)"""""
It is expressed as (4).

At this time, if d l l/2 < d Rl/2, the following formulas (5) to (7) hold true.

d L l/2 +d, Rl/2≧d L Rl /
2 , , , , , -(5) 2dI-l/2≧d
LR"' (6) dL ≧dLR/4
(7) This strain temperature dL is obtained from the input vector Ma1 and the left reference vector 〒L using the above equation (2), and the above (7
) If the equation (7) is not satisfied, the input vector zo is close to the left reference vector 〒L; conversely, if this equation (7) is satisfied, the human power vector zo and the right reference vector A similar determination can be made.

This can be explained concretely by taking as an example the case where the input vector Ma, the left reference vector 〒, and the right reference vector 〒 are all one-dimensional vectors XXT+, , TR, as shown in Figure 1. explain. In addition, in the same figure (a), the human power vector χ is the left reference vector TL and the right reference vector TR.
In the case where the human force vector X is between the ranges of the left reference vector T and the right reference vector T, FIG.

Assuming that the left reference vector T+ = 14 and the right reference vector TR-6, the strain temperature dLR between these reference vectors is aLR-(Tt-TR) 2-(14-6) 2-8
2=64, so the scalar quantity (ILR/4=16).

Table 1 shows the values of the two reference vectors as the left reference vector T
The table below shows each position when the input vector X is in the range of 4 to 24, assuming that t=14 and the right reference vector TR=6.

Table 1 As is clear from this example, when dL<dLR/4, the human vector X is close to the left reference vector TL, and dLR/4 is the left reference vector TL assigned to this node. This is a value that can be calculated in advance from the right reference vector T, and the right reference vector T.

Therefore, each node has a left reference vector TL, a right reference vector T, and a strain temperature d between the reference vectors.
Given the value of LR/4, first calculate the strain temperature dL between the human power vector
If the condition dLR/4 is satisfied, it is sufficient to branch to the left reference vector calculation side, and the right reference vector T
, there is no need to calculate the strain temperature.

At this time, if dL≧dLR/4, the strain temperature d for the right reference vector TR is similar to the conventional branch selection.
It is sufficient to calculate R and branch to either the left reference vector T1 or the right reference vector TR, whichever is closer, and the frequency with which this calculation should be performed can be reduced by selecting these two reference vectors.

In general, multidimensional vector operations take longer to process as the number of dimensions increases, so the ability to reduce the frequency of vector operations for one of the reference vectors with the present invention significantly reduces the overall processing time. It has the extraordinary effect of being able to

An example will be described in which the following equation (8) is used as the strain temperature in place of the square strain of equation (1) above.

Here, 71 is an element of the human vector sentence, and τ is an element of the reference vector, as in the case of equation (1),
The difference is that the absolute value of the difference between these vectors is used as the strain temperature.

In this embodiment, the following judgment formula is used instead of the branch judgment using the above equation (7).

dL>dLR/2 (9) This strain temperature dL is expressed as the human power vector Sentence 1 and the left reference vector 〒L
If the above formula (9) is not satisfied, the input vector sentence is close to the left reference vector 〒L,
On the other hand, if this equation (7) is satisfied, the distortion temperature dR between the human vector sentence and the right reference vector 〒R may be determined, and the same determination as in the conventional method may be performed.

The following Table 2 shows, as shown in Table 1, when the input vector The determination results according to this example are shown for the state of .

Table 2 It will be clear that the results are similar to those in Table 1.

[Effect] In general, multidimensional vector operations require a longer time to process as the number of dimensions increases. This has the special effect of significantly shortening the time.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between an input vector and two reference vectors, Figure 2 is an illustration of matching using a binary tree, and Figure 3 is an explanation of how to generate a binary tree for this matching. This is a diagram. X...input vector, TL, T,...reference vector, dL and dR...distortion temperature between the input vector and reference vector, dLR...distortion temperature between the reference vector. Patent applicant Rico Co., Ltd. - (a) (b) Figure 1 n Figure 2

Claims (3)

[Claims] (1) In order to determine the branch direction at a node in the binary tree, in addition to two reference vectors (■_L, ■_R) for determining the direction to branch, the node has a distortion measure between these reference vectors. (dLR) is given as a scalar quantity, and the input vector (■) and one of the above reference vectors (■_L
) A method for determining a branching direction in a binary tree, characterized in that a branching toward one reference vector can be determined based only on the magnitude relationship between the distortion measure and the scalar amount. (2) Use a square strain measure as the strain measure, and use 1/4 (dLR) of the strain measure between the reference vectors as a scalar quantity.
2. A branching direction determination method in a binary tree according to claim 1, characterized in that the branching direction determination method in a binary tree uses the following: /4). (3) Use the absolute value of the vector difference as the distortion measure, and use 1/1/2 of the distortion measure between the reference vectors as a scalar quantity.
2. The branching direction determination method in a binary tree according to claim 1, wherein dLR/2 is used.