Median Filter
Median filter
- Library:
DSP System Toolbox / Filtering / Filter Designs
DSP System Toolbox / Statistics
Description
The Median Filter block computes the moving median of the input signal along each channel independently over time. The block uses the sliding window method to compute the moving median. In this method, a window of specified length moves over each channel sample by sample, and the block computes the median of the data in the window. This block performs median filtering on the input data over time. For more details, see Algorithms.
Ports
Input
Output
Parameters
Block Characteristics
Data Types |
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Multidimensional Signals |
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Variable-Size Signals |
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Algorithms
Sliding Window Method
In the sliding window method, the output for each input sample is the median of the current sample and the Len - 1 previous samples. Len is the length of the window in samples. To compute the first Len - 1 outputs, when the window does not have enough data yet, the algorithm fills the window with zeros. As an example, to compute the median value when the second input sample comes in, the algorithm fills the window with Len - 2 zeros. The data vector, x, is then the two data samples followed by Len - 2 zeros. This object performs median filtering on the input data over time.
Consider an example of computing the moving median of a streaming input data using the sliding window method. The algorithm uses a window length of 4. With each input sample that comes in, the window of length 4 moves along the data.
Extended Capabilities
See Also
Blocks
- Median | Moving Average | Moving Maximum | Moving Minimum | Moving RMS | Moving Standard Deviation | Moving Variance