Please cite SAGA whenever you use it for your publications:

Rank filter for grids. Set rank to fifty percent to apply a median filter.

Name	Type	Identifier	Description	Constraints
Input
Grid	grid, input	INPUT
Output
Filtered Grid	grid, output, optional	RESULT
Options
Rank	floating point number	RANK	The rank [percent].	Minimum: 0.000000 Maximum: 100.000000 Default: 50
Kernel Type	choice	KERNEL_TYPE	The kernel's shape.	Available Choices: [0] Square [1] Circle Default: 1
Radius	integer number	KERNEL_RADIUS	cells	Minimum: 0 Default: 2