matlab upsampling,Dyadic upsampling

dyadup

Dyadic upsampling

Syntax

Y = dyadup(X,EVENODD)

Y = dyadup(X)

Y = dyadup(X,EVENODD,'type')

Y

= dyadup(X,'type',EVENODD)

Y = dyadup(X)

Y = dyaddown(X,1,'c')

Y = dyadup(X,'type')

Y = dyadup(X,1,'type')

Y = dyadup(X,EVENODD)

Y = dyadup(X,EVENODD,'c')

Description

dyadup implements a simple zero-padding scheme very useful in the wavelet

reconstruction algorithm.

Y = dyadup(X,EVENODD), where X is

a vector, returns an extended copy of vector X obtained

by inserting zeros. Whether the zeros are inserted as even- or odd-indexed

elements of Y depends on the value of positive

integer EVENODD:

If EVENODD is even, then Y(2k–1)

= X(k), Y(2k) = 0.

If EVENODD is odd, then Y(2k–1)

= 0, Y(2k) = X(k).

Y = dyadup(X) is

equivalent to Y = dyadup(X,1) (odd-indexed

samples).

Y = dyadup(X,EVENODD,'type') or Y

= dyadup(X,'type',EVENODD),

where X is a matrix,

returns extended copies of X obtained by

inserting

Columns in XIf 'type'= 'c'

Rows in XIf 'type'= 'r'

Rows and columns in XIf 'type'= 'm'

according to the parameter EVENODD,

which is as above.

If you omit the EVENODD or 'type'

arguments, dyadup defaults to EVENODD = 1 (zeros

in odd-indexed positions) and 'type'= 'c'

(insert columns).

Y = dyadup(X) is

equivalent to Y = dyaddown(X,1,'c').

Y = dyadup(X,'type') is

equivalent to Y = dyadup(X,1,'type').

Y = dyadup(X,EVENODD) is

equivalent to Y = dyadup(X,EVENODD,'c').

Examples

% For a vector.

s = 1:5

s =

1 2 3 4 5

dse = dyadup(s) % Upsample elements at odd indices.

dse =

0 1 0 2 0 3 0 4 0 5 0

% or equivalently

dse = dyadup(s,1)

dse =

0 1 0 2 0 3 0 4 0 5 0

dso = dyadup(s,0) % Upsample elements at even indices.

dso =

1 0 2 0 3 0 4 0 5

% For a matrix.

s = (1:2)'*(1:3)

s =

1 2 3

2 4 6

der = dyadup(s,1,'r') % Upsample rows at even indices.

der =

0 0 0

1 2 3

0 0 0

2 4 6

0 0 0

doc = dyadup(s,0,'c') % Upsample columns at odd indices.

doc =

1 0 2 0 3

2 0 4 0 6

dem = dyadup(s,1,'m') % Upsample rows and columns

% at even indices.

dem =

0 0 0 0 0 0 0

0 1 0 2 0 3 0

0 0 0 0 0 0 0

0 2 0 4 0 6 0

0 0 0 0 0 0 0

% Using default values for dyadup and dyaddown, we have:

% dyaddown(dyadup(s)) = s.

s = 1:5

s =

1 2 3 4 5

uds = dyaddown(dyadup(s))

uds =

1 2 3 4 5

% In general reversed identity is false.

References

Strang, G.; T. Nguyen (1996), Wavelets and Filter

Banks, Wellesley-Cambridge Press.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

If X is empty, generated code returns X and MATLAB® returns [].

Suppose that all of

the following conditions are true:

X is a variable-size array.

X is not a variable-length column

vector (:-by-1).

X is a column vector at run time.

'type' is

not supplied.

In generated code, the output for y = dyadup(X,k),

where k is optional, matches the output for y

= dyadup(X,k,'c'). In MATLAB, the output for y

= dyadup(X,k) matches the output for y = dyadup(X,k,'r').

For code generation, when you do not specify 'type',

if you want dyadup to treat X as

a column vector, X must be a variable-length vector

(:-by-1).

GPU Arrays

Accelerate code by running on a graphics processing unit (GPU) using Parallel Computing Toolbox™.

This function fully supports GPU arrays. For more information, see Run MATLAB Functions on a GPU(Parallel Computing Toolbox).

See Also

Introduced before R2006a