template struct mrpt::maps::CLogOddsGridMapLUT

Overview

One static instance of this struct should exist in any class implementing CLogOddsGridMap2D to hold the Look-up-tables (LUTs) for log-odss Bayesian update.

Map cells must be type TCELL, which can be only:

• int8_t or

• int16_t

See also:

CLogOddsGridMap2D, see derived classes for usage examples.

#include <mrpt/maps/CLogOddsGridMapLUT.h>

template <typename TCELL>
struct CLogOddsGridMapLUT: public mrpt::maps::detail::logoddscell_traits
{
    // typedefs

    typedef TCELL cell_t;
    typedef detail::logoddscell_traits<TCELL> traits_t;

    // fields

    std::vector<float> logoddsTable;
    std::vector<uint8_t> logoddsTable_255;
    std::vector<cell_t> p2lTable;

    // construction

    CLogOddsGridMapLUT();

    // methods

    float l2p(const cell_t l);
    uint8_t l2p_255(const cell_t l);
    cell_t p2l(const float p);
};

Typedefs

typedef TCELL cell_t

The type of.

Fields

std::vector<float> logoddsTable

A lookup table to compute occupancy probabilities in [0,1] from integer log-odds values in the cells, using \(p(m_{xy}) = \frac{1}{1+exp(-log_odd)}\).

std::vector<uint8_t> logoddsTable_255

A lookup table to compute occupancy probabilities in the range [0,255] from integer log-odds values in the cells, using \(p(m_{xy}) = \frac{1}{1+exp(-log_odd)}\).

This is used to speed-up conversions to grayscale images.

std::vector<cell_t> p2lTable

A lookup table for passing from float to log-odds as cell_t.

Construction

CLogOddsGridMapLUT()

Constructor: computes all the required stuff.

Methods

float l2p(const cell_t l)

Scales an integer representation of the log-odd into a real valued probability in [0,1], using p=exp(l)/(1+exp(l))

uint8_t l2p_255(const cell_t l)

Scales an integer representation of the log-odd into a linear scale [0,255], using p=exp(l)/(1+exp(l))

cell_t p2l(const float p)

Scales a real valued probability in [0,1] to an integer representation of: log(p)-log(1-p) in the valid range of cell_t.