Skip to main content

NDArray::convolve2d

public static function convolve2d(NDArray|array $a, NDArray|array $b, string $mode, string $boundary, float $fill_value = 0.0): NDArray;

Convolve two 2-dimensional arrays.

Convolve $a and $b with output size determined by $mode, and boundary conditions determined by $boundary and $fill_value.

$mode options​

  • full - Full discrete linear convolution of the inputs
  • valid - The output consists only of those elements that do not rely on the zero-padding. In ‘valid’ mode, either $a or $b must be at least as large as the other in every dimension.
  • same - The output is the same size as $a, centered with respect to the ‘full’ output.

$boundary options​

  • fill - Pad input arrays with $fill_value
  • wrap - Circular boundary
  • symm - Symmetrical boundary

Parameters​

$a $b​

  • Type - NDArray | array | GdImage
  • The arrays to perform the convolution.

$mode​

  • Type - string
  • The size of the output. Can be: full, valid and same

$boundary​

  • Type - string
  • A flag indicating how to handle boundaries. Can be: fill, wrap and symm

Notes​

tip

GPU SUPPORTED​

This operation is supported by GPU (VRAM) and contains a custom CUDA kernel.