2-D Autocorrelation

2-D autocorrelation of input matrix

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  • Library:

  • Computer Vision Toolbox / Statistics

  • 2-D Autocorrelation block

Description

The 2-D Autocorrelation block computes the 2-D autocorrelation of the input vector or matrix.

Ports

Input

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Input array, specified as a vector or matrix.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32 | fixed point
Complex Number Support: Yes

Output

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Autocorrelation of the input array, returned as a vector or matrix. The data type of the output is the same as that of the input.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32 | fixed point
Complex Number Support: Yes

Parameters

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For details on fixed-point block parameters, see Specify Fixed-Point Attributes for Blocks.

Select this parameter to prevent the fixed-point tools from overriding the data types you specify in this block. For more information, see Lock the Output Data Type Setting (Fixed-Point Designer).

Model Examples

Compute Autocorrelation of Input Matrix

Compute Autocorrelation of Input Matrix

Compute autocorrelation of a 5-by-5 input matrix using the 2-D Autocorrelation block.

Block Characteristics

Data Types

double | fixed point | integer | single

Multidimensional Signals

no

Variable-Size Signals

yes

Algorithms

If the input Ais a vector with dimension M-by-1 then the equation for 1-D discrete autocorrelation is:

C(n)=∑m=0M−1A(m)∗A(m+n)

where 0≤n≤2M−1 .

The output is an autocorrelation vector of size (2M−1,1).

If the input A is a matrix with dimension M-by-N then the equation for the 2-D discrete autocorrelation is:

C(i,j)=∑m=0(M−1)∑n=0(N−1)A(m,n)⋅conj(A(m+i,n+j))

where 0≤i<2M−1 and 0≤j<2N−1.

The dimension of the output autocorrelation matrix is (2M−1,2N−1).

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

See Also

Blocks

Introduced before R2006a

Computer Vision Toolbox Documentation

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