Method createZImin

filters/SMRFilter.cpp:476–521

}

std::vector<double> SMRFilter::createZImin(PointViewPtr view)
{
    // "As with many other ground filtering algorithms, the first step is
    // generation of ZImin from the cell size parameter and the extent of the
    // data."
    std::vector<double> ZIminV(m_rows * m_cols,
                               std::numeric_limits<double>::quiet_NaN());

    for (PointRef p : *view)
    {
        double x = p.getFieldAs<double>(Id::X);
        double y = p.getFieldAs<double>(Id::Y);
        double z = p.getFieldAs<double>(Id::Z);

        int c = static_cast<int>(floor((x - m_bounds.minx) / m_args->m_cell));
        int r = static_cast<int>(floor((y - m_bounds.miny) / m_args->m_cell));

        size_t cell = c * m_rows + r;
        if (z < ZIminV[cell] || std::isnan(ZIminV[cell]))
            ZIminV[cell] = z;
    }

    // "...some grid points of ZImin will go unfilled. To fill these values, we
    // rely on computationally inexpensive image inpainting techniques. Image
    // inpainting involves the replacement of the empty cells in an image (or
    // matrix) with values calculated from other nearby values."

    //ABELL - We can eliminate this copy if we're OK with not writing
    //  both the filled and non-filled array to output.
    std::vector<double> ZImin_fillV = ZIminV;
    knnfill(view, ZImin_fillV);

    if (!m_args->m_dir.empty())
    {
        std::string fname =
            FileUtils::toAbsolutePath("zimin.tif", m_args->m_dir);
        MatrixXd ZImin = Map<MatrixXd>(ZIminV.data(), m_rows, m_cols);
        math::writeMatrix(ZImin, fname, "GTiff", m_args->m_cell, m_bounds, m_srs);

        fname = FileUtils::toAbsolutePath("zimin_fill.tif", m_args->m_dir);
        MatrixXd ZImin_fill = Map<MatrixXd>(ZImin_fillV.data(), m_rows, m_cols);
        math::writeMatrix(ZImin_fill, fname, "GTiff", m_args->m_cell, m_bounds, m_srs);
    }

    return ZImin_fillV;
}

std::vector<double> SMRFilter::createZInet(std::vector<double> const& ZImin,
                                           std::vector<int> const& isNetCell)