iclass_signatures.c

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/*!
   \file lib/imagery/iclass_statistics.c
 
   \brief Imagery library - functions for wx.iclass
 
   Computation based on training areas for supervised classification.
   Based on i.class module (GRASS 6).
 
   Computation and writing signatures to file.
 
   SPDX-FileCopyrightText: 1999-2007, 2011 GRASS Development Team
   SPDX-License-Identifier: GPL-2.0-or-later
 
   \author David Satnik, Central Washington University (original author)
   \author Markus Neteler <neteler itc.it> (i.class module)
   \author Bernhard Reiter <bernhard intevation.de> (i.class module)
   \author Brad Douglas <rez touchofmadness.com>(i.class module)
   \author Glynn Clements <glynn gclements.plus.com> (i.class module)
   \author Hamish Bowman <hamish_b yahoo.com> (i.class module)
   \author Jan-Oliver Wagner <jan intevation.de> (i.class module)
   \author Anna Kratochvilova <kratochanna gmail.com> (rewriting for wx.iclass)
   \author Vaclav Petras <wenzeslaus gmail.com> (rewriting for wx.iclass)
 */
 
#include <string.h>
#include <stdio.h>
 
#include <grass/imagery.h>
#include <grass/glocale.h>
#include <grass/colors.h>
 
#include "iclass_local_proto.h"
 
/*!
   \brief Initialize signatures.
 
   \param[out] sigs pointer to signatures
   \param refer pointer to band files structure
 
   \return 1 on success
   \return 0 on failure
 */
int I_iclass_init_signatures(struct Signature *sigs, struct Ref *refer)
{
    G_debug(3, "I_iclass_init_signatures()");
 
    I_init_signatures(sigs, refer->nfiles);
    for (unsigned int i = refer->nfiles; i--;) {
        sigs->semantic_labels[i] = Rast_get_semantic_label_or_name(
            refer->file[i].name, refer->file[i].mapset);
    }
 
    return 1;
}
 
/*!
   \brief Add one signature.
 
   \param[out] sigs pointer to signatures
   \param statistics pointer to statistics structure
 */
void I_iclass_add_signature(struct Signature *sigs,
                            IClass_statistics *statistics)
{
    int sn;
 
    int b1, b2;
 
    int r, g, b;
 
    G_debug(3, "I_iclass_add_signature()");
 
    G_str_to_color(statistics->color, &r, &g, &b);
 
    /* get a new signature */
    I_new_signature(sigs);
 
    /* save the signature in a Sig structure */
    sn = sigs->nsigs;
    strcpy(sigs->sig[sn - 1].desc, statistics->name);
    sigs->sig[sn - 1].npoints = statistics->ncells;
    sigs->sig[sn - 1].status = 1;
 
    sigs->sig[sn - 1].have_color = 1;
    sigs->sig[sn - 1].r = r;
    sigs->sig[sn - 1].g = g;
    sigs->sig[sn - 1].b = b;
 
    for (b1 = 0; b1 < sigs->nbands; b1++) {
        sigs->sig[sn - 1].mean[b1] = statistics->band_mean[b1];
        for (b2 = 0; b2 <= b1; b2++) {
            sigs->sig[sn - 1].var[b1][b2] = var_signature(statistics, b1, b2);
        }
    }
}
 
/*!
   \brief Write signtures to signature file.
 
   \param sigs pointer to signatures
   \param file_name name of signature file
 
   \return 1 on success
   \return 0 on failure
 */
int I_iclass_write_signatures(struct Signature *sigs, const char *file_name)
{
    FILE *outsig_fd;
 
    G_debug(3, "I_write_signatures(): file_name=%s", file_name);
 
    if (!(outsig_fd = I_fopen_signature_file_new(file_name))) {
        G_warning(_("Unable to open output signature file '%s'"), file_name);
        return 0;
    }
 
    I_write_signatures(outsig_fd, sigs);
    fclose(outsig_fd);
 
    return 1;
}