NumCpp  2.5.1
A Templatized Header Only C++ Implementation of the Python NumPy Library
rankFilter.hpp
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1 #pragma once
29 
31 #include "NumCpp/Core/Shape.hpp"
32 #include "NumCpp/Core/Slice.hpp"
33 #include "NumCpp/Core/Types.hpp"
36 #include "NumCpp/NdArray.hpp"
37 
38 #include <string>
39 
40 namespace nc
41 {
42  namespace filter
43  {
44  //============================================================================
45  // Method Description:
58  template<typename dtype>
59  NdArray<dtype> rankFilter(const NdArray<dtype>& inImageArray, uint32 inSize, uint32 inRank,
60  Boundary inBoundaryType = Boundary::REFLECT, dtype inConstantValue = 0)
61  {
62  if (inRank >= utils::sqr(inSize))
63  {
64  THROW_INVALID_ARGUMENT_ERROR("rank not within filter footprint size.");
65  }
66 
67  NdArray<dtype> arrayWithBoundary = boundary::addBoundary2d(inImageArray, inBoundaryType, inSize, inConstantValue);
68  NdArray<dtype> output(inImageArray.shape());
69 
70  const Shape inShape = inImageArray.shape();
71  const uint32 boundarySize = inSize / 2; // integer division
72  const uint32 endPointRow = boundarySize + inShape.rows;
73  const uint32 endPointCol = boundarySize + inShape.cols;
74 
75  for (uint32 row = boundarySize; row < endPointRow; ++row)
76  {
77  for (uint32 col = boundarySize; col < endPointCol; ++col)
78  {
79  NdArray<dtype> window = arrayWithBoundary(Slice(row - boundarySize, row + boundarySize + 1),
80  Slice(col - boundarySize, col + boundarySize + 1));
81 
82  output(row - boundarySize, col - boundarySize) = sort(window)[inRank];
83  }
84  }
85 
86  return output;
87  }
88  } // namespace filter
89 } // namespace nc
#define THROW_INVALID_ARGUMENT_ERROR(msg)
Definition: Error.hpp:36
Holds 1D and 2D arrays, the main work horse of the NumCpp library.
Definition: NdArrayCore.hpp:72
Shape shape() const noexcept
Definition: NdArrayCore.hpp:4483
A Shape Class for NdArrays.
Definition: Core/Shape.hpp:41
uint32 rows
Definition: Core/Shape.hpp:44
uint32 cols
Definition: Core/Shape.hpp:45
A Class for slicing into NdArrays.
Definition: Slice.hpp:44
NdArray< dtype > addBoundary2d(const NdArray< dtype > &inImage, Boundary inBoundaryType, uint32 inKernalSize, dtype inConstantValue=0)
Definition: addBoundary2d.hpp:61
NdArray< dtype > rankFilter(const NdArray< dtype > &inImageArray, uint32 inSize, uint32 inRank, Boundary inBoundaryType=Boundary::REFLECT, dtype inConstantValue=0)
Definition: rankFilter.hpp:59
Boundary
Boundary condition to apply to the image filter.
Definition: Boundary.hpp:37
constexpr dtype sqr(dtype inValue) noexcept
Definition: sqr.hpp:44
Definition: Coordinate.hpp:45
NdArray< dtype > sort(const NdArray< dtype > &inArray, Axis inAxis=Axis::NONE)
Definition: sort.hpp:47
std::uint32_t uint32
Definition: Types.hpp:40