dsp.ScalarQuantizerEncoder System object
Package: dsp
Associate input value with index value of quantization region
Description
The ScalarQuantizerEncoder object encodes
each input value by associating that value with the index value of
the quantization region. Then, the object outputs the index of the
associated region.
To encode an input value by associating it with an index value of the quantization region:
Define and set up your scalar quantizer encoder. See Construction.
Call
stepto encode the input value according to the properties ofdsp.ScalarQuantizerEncoder. The behavior ofstepis specific to each object in the toolbox.
Note:
Starting in R2016b, instead of using the |
Construction
H = dsp.ScalarQuantizerEncoder returns
a scalar quantizer encoder System object, H.
This object maps each input value to a quantization region by comparing
the input value to the user-specified boundary points.
H = dsp.ScalarQuantizerEncoder(' returns
a scalar quantizer encoder object, PropertyName',PropertyValue,...)H, with each specified
property set to the specified value.
Properties
|
Source of boundary points Specify how to determine the boundary points and codebook values
as |
|
Quantizer is bounded or unbounded Specify the quantizer as |
|
Boundary points of quantizer regions Specify the boundary points of quantizer regions as a vector.
The vector values must be in ascending order. Let |
|
Find quantizer index by linear or binary search Specify whether to find the appropriate quantizer index using
a linear search or a binary search as one of where P is
the number of boundary points. The default is |
|
Behavior when input equals boundary point Specify whether the input value is assigned to the lower indexed
region or higher indexed region when the input value equals boundary
point by selecting |
|
Enable output of codeword value Set this property to |
|
Enable output of quantization error Set this property to |
|
Codebook Specify the codebook as a vector of quantized output values
that correspond to each region. If the |
|
Enable output of clipping status Set this property to |
|
Data type of the index output Specify the data type of the index output from the object as: |
Methods
| clone | Create an instance of an object with the same property values |
| getNumInputs | Number of expected inputs to step method |
| getNumOutputs | Number of outputs of step method |
| isLocked | Locked status for input attributes and nontunable properties |
| release | Allow property value and input characteristics changes |
| step | Encode using scalar quantization |
Examples
Quantize the Varying Fractional Inputs
Note: This example runs only in R2016b or later. If you are using an earlier release, replace each call to the function with the equivalent step syntax. For example, myObject(x) becomes step(myObject,x).
Quantize the varying fractional inputs between zero and five to the closest integers, and then plot the results.
hsqe = dsp.ScalarQuantizerEncoder;
hsqe.BoundaryPoints = [-.001 .499 1.499 ...
2.499 3.499 4.499 5.001];
hsqe.CodewordOutputPort = true;
hsqe.Codebook = [0 1 2 3 4 5];
input = (0:0.02:5)';
[index, quantizedValue] = hsqe(input);
plot(1:length(input), [input quantizedValue]);
Algorithms
This object implements the algorithm, inputs, and outputs described on the Scalar Quantizer Encoder block reference page. The object properties correspond to the block parameters.