filter2 {EBImage} | R Documentation

## 2D Convolution Filter

### Description

2D convolution-based linear filter for images and matrix data.

### Usage

      ## S4 methods for signatures 'x=Image' or 'x=array' and
      ## 'filter=matrix' or 'filter=missing'
      filter2(x, filter, ...)

      ## S4 method for signature 'Image':
      sharpen2(x, ...)

      mkball(n=15, pow=1)
      mkbox(n=15)

### Arguments

`x` | An object of `Image` in Grayscale mode, a numeric `array` or a `matrix`.
`filter` | A square matrix with odd dimensions.
`n` | The size of the filter matrix (odd number).
`pow` | The power of the function used to fill in the matrix.
`...` | Reserved.

### Details

The convolution filter is based on `fft` transforms.

If `x` is an `array`, the filter is applied per frame (as to images).

`sharpen2` uses `filter2` to sharpen grayscale images by subtracting a slightly blurred image with the center pixel excluded.

### Value

`filter2` and `` return a transformed object of the same class as `x`.
`mkball` and `mkbox` return a square matrix that can be used for `filter2`.

### Author(s)

`filter2` author: Gregoire Pau, gpau@ebi.ac.uk, 2007

`sharpen2` author: Oleg Sklyar, osklyar@ebi.ac.uk, 2007

### See Also

`Image, fft`

[Package EBImage version 2.4.0 Index]