GDAL

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GDALIntegralImage Class Reference

Integral image class (summed area table). More...

`#include <gdal_simplesurf.h>`

## Public Member Functions
void | Initialize (const double **padfImg, int nHeight, int nWidth)
| Compute integral image for specified array.
double | GetValue (int nRow, int nCol)
| Fetch value of specified position in integral image.
double | GetRectangleSum (int nRow, int nCol, int nWidth, int nHeight)
| Get sum of values in specified rectangular grid.
double | HaarWavelet_X (int nRow, int nCol, int nSize)
| Get value of horizontal Haar wavelet in specified square grid.
double | HaarWavelet_Y (int nRow, int nCol, int nSize)
| Get value of vertical Haar wavelet in specified square grid.
int | GetHeight ()
| Fetch height of integral image.
int | GetWidth ()
| Fetch width of integral image.

## Detailed Description

Integral image class (summed area table).

Author
  Andrew Migal migal.drew at gmail.com

Integral image is a table for fast computing the sum of values in rectangular subarea. In more detail, for 2-dimensional array of numbers this class provides capability to get sum of values in rectangular arbitrary area with any size in constant time. Integral image is constructed from grayscale picture.

## Member Function Documentation

## ◆ GetHeight()

int GDALIntegralImage::GetHeight | ( |  | ) |

Fetch height of integral image.

Returns
  Height of integral image (number of rows).

## ◆ GetRectangleSum()

double GDALIntegralImage::GetRectangleSum | ( | int | nRow,
|  | int | nCol,
|  | int | nWidth,
|  | int | nHeight
| ) |  |

Get sum of values in specified rectangular grid.

Rectangle is constructed from left top point.

Parameters

  nRow | Row of left top point of rectangle
  nCol | Column of left top point of rectangle
  nWidth | Width of rectangular area (number of columns)
  nHeight | Height of rectangular area (number of rows)

Returns
  Sum of values in specified grid.

## ◆ GetValue()

double GDALIntegralImage::GetValue | ( | int | nRow,
|  | int | nCol
| ) |  |

Fetch value of specified position in integral image.

Parameters

  nRow | Row of this position
  nCol | Column of this position

Returns
  Value in specified position or zero if parameters are out of range.

## ◆ GetWidth()

int GDALIntegralImage::GetWidth | ( |  | ) |

Fetch width of integral image.

Returns
  Width of integral image (number of columns).

## ◆ HaarWavelet_X()

double GDALIntegralImage::HaarWavelet_X | ( | int | nRow,
|  | int | nCol,
|  | int | nSize
| ) |  |

Get value of horizontal Haar wavelet in specified square grid.

Parameters

  nRow | Row of left top point of square
  nCol | Column of left top point of square
  nSize | Side of the square

Returns
  Value of horizontal Haar wavelet in specified square grid.

## ◆ HaarWavelet_Y()

double GDALIntegralImage::HaarWavelet_Y | ( | int | nRow,
|  | int | nCol,
|  | int | nSize
| ) |  |

Get value of vertical Haar wavelet in specified square grid.

Parameters

  nRow | Row of left top point of square
  nCol | Column of left top point of square
  nSize | Side of the square

Returns
  Value of vertical Haar wavelet in specified square grid.

## ◆ Initialize()

void GDALIntegralImage::Initialize | ( | const double ** | padfImg,
|  | int | nHeight,
|  | int | nWidth
| ) |  |

Compute integral image for specified array.

Result is stored internally.

Parameters

  padfImg | Pointer to 2-dimensional array of values
  nHeight | Number of rows in array
  nWidth | Number of columns in array

The documentation for this class was generated from the following files:

- gdal_simplesurf.h
- gdal_octave.cpp