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.

   Copyright (C) 1999-2007, 2011 by the GRASS Development Team

   This program is free software under the GNU General Public License
   (>=v2).  Read the file COPYING that comes with GRASS for details.

   \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()");

    if (!I_init_signatures(sigs, refer->nfiles))
        return 1;               /* success */

    return 0;
}

/*!
   \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 group image group
   \param sub_group image subgroup
   \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 *group,
                              const char *sub_group, const char *file_name)
{
    FILE *outsig_fd;

    G_debug(3, "I_write_signatures(): group=%s, file_name=%s", group,
            file_name);

    if (!
        (outsig_fd =
         I_fopen_signature_file_new(group, sub_group, 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;
}