Public Member Functions | Public Attributes | Static Public Attributes

# GDALOctaveMap Class Reference

Class for handling octave layers in SURF-based algorithm. More...

`#include <gdal_simplesurf.h>`

List of all members.

## Public Member Functions
| GDALOctaveMap (int nOctaveStart, int nOctaveEnd)
| Create octave space.
void | ComputeMap (GDALIntegralImage *poImg)
| Calculate Hessian values for octave space (for all stored octave layers) using specified integral image.
bool | PointIsExtremum (int row, int col, GDALOctaveLayer *bot, GDALOctaveLayer *mid, GDALOctaveLayer *top, double threshold)
| Method makes decision that specified point in middle octave layer is maximum among all points from 3x3x3 neighbourhood (surrounding points in bottom, middle and top layers).
## Public Attributes
GDALOctaveLayer *** | pMap
| 2-dimensional array of octave layers
int | octaveStart
| Number of bottom octave.
int | octaveEnd
| Number of top octave.
## Static Public Attributes
static const int | INTERVALS = 4
| Value for constructing internal octave space.

## Detailed Description

Class for handling octave layers in SURF-based algorithm.

Author:
  Andrew Migal migal.drew@gmail.com

Class contains OctaveLayers and provides capability to construct octave space and distinguish feature points. Normally this class is used only by SURF-based algorithm.

## Constructor & Destructor Documentation

GDALOctaveMap::GDALOctaveMap | ( | int | nOctaveStart,
|  | int | nOctaveEnd |
| ) |  |  |

Create octave space.

Octave numbers are start with one. (1, 2, 3, 4, ... )

Parameters:

  | nOctaveStart | Number of bottom octave
  | nOctaveEnd | Number of top octave. Should be equal or greater than OctaveStart

## Member Function Documentation

void GDALOctaveMap::ComputeMap | ( | GDALIntegralImage * | poImg | ) |

Calculate Hessian values for octave space (for all stored octave layers) using specified integral image.

Parameters:

  | poImg | Integral image instance which provides necessary data

See also:
  GDALOctaveLayer

bool GDALOctaveMap::PointIsExtremum | ( | int | row,
|  | int | col,
|  | GDALOctaveLayer * | bot,
|  | GDALOctaveLayer * | mid,
|  | GDALOctaveLayer * | top,
|  | double | threshold |
| ) |  |  |

Method makes decision that specified point in middle octave layer is maximum among all points from 3x3x3 neighbourhood (surrounding points in bottom, middle and top layers).

Provided layers should be from the same octave's interval. Detects feature points.

Parameters:

  | row | Row of point, which is candidate to be feature point
  | col | Column of point, which is candidate to be feature point
  | bot | Bottom octave layer
  | mid | Middle octave layer
  | top | Top octave layer
  | threshold | Threshold for feature point recognition. Detected feature point will have Hessian value greater than this provided threshold.

Returns:
  TRUE if candidate was evaluated as feature point or FALSE otherwise.

## Member Data Documentation

int GDALOctaveMap::octaveEnd

Number of top octave.

Should be equal or greater than OctaveStart

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

- gdal_simplesurf.h
- gdal_octave.cpp

Generated for GDAL by 1.7.1.