/* pgmtexture.c - calculate textural features on a portable graymap
**
** Author: James Darrell McCauley
**         Texas Agricultural Experiment Station
**         Department of Agricultural Engineering
**         Texas A&M University
**         College Station, Texas 77843-2117 USA
**
** Code written partially taken from pgmtofs.c in the PBMPLUS package
** by Jef Poskanzer.
**
** Algorithms for calculating features (and some explanatory comments) are
** taken from:
**
**   Haralick, R.M., K. Shanmugam, and I. Dinstein. 1973. Textural features
**   for image classification.  IEEE Transactions on Systems, Man, and
**   Cybertinetics, SMC-3(6):610-621.
**
** Copyright (C) 1991 Texas Agricultural Experiment Station, employer for
** hire of James Darrell McCauley
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation.  This software is provided "as is" without express or
** implied warranty.
**
** THE TEXAS AGRICULTURAL EXPERIMENT STATION (TAES) AND THE TEXAS A&M
** UNIVERSITY SYSTEM (TAMUS) MAKE NO EXPRESS OR IMPLIED WARRANTIES
** (INCLUDING BY WAY OF EXAMPLE, MERCHANTABILITY) WITH RESPECT TO ANY
** ITEM, AND SHALL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL
** OR CONSEQUENTAL DAMAGES ARISING OUT OF THE POSESSION OR USE OF
** ANY SUCH ITEM. LICENSEE AND/OR USER AGREES TO INDEMNIFY AND HOLD
** TAES AND TAMUS HARMLESS FROM ANY CLAIMS ARISING OUT OF THE USE OR
** POSSESSION OF SUCH ITEMS.
** 
** Modification History:
** 24 Jun 91 - J. Michael Carstensen <jmc@imsor.dth.dk> supplied fix for 
**             correlation function.
**
** 05 Oct 05 - Marc Breithecker <Marc.Breithecker@informatik.uni-erlangen.de>
**             Fix calculation or normalizing constants for d > 1.
*/

#include <math.h>

#include "pm_c_util.h"
#include "pgm.h"
#include "mallocvar.h"

#define RADIX 2.0
#define EPSILON 0.000000001
#define BL  "Angle                 "
#define F1  "Angular Second Moment "
#define F2  "Contrast              "
#define F3  "Correlation           "
#define F4  "Variance              "
#define F5  "Inverse Diff Moment   "
#define F6  "Sum Average           "
#define F7  "Sum Variance          "
#define F8  "Sum Entropy           "
#define F9  "Entropy               "
#define F10 "Difference Variance   "
#define F11 "Difference Entropy    "
#define F12 "Meas of Correlation-1 "
#define F13 "Meas of Correlation-2 "
#define F14 "Max Correlation Coeff "

#define SIGN(x,y) ((y)<0 ? -fabs(x) : fabs(x))
#define DOT fprintf(stderr,".")
#define SWAP(a,b) {y=(a);(a)=(b);(b)=y;}


static bool sortit = FALSE;

static float *
vector (int nl, int nh)
{
    float *v;

    MALLOCARRAY(v, (unsigned) (nh - nl + 1));
    if (v == NULL)
        pm_error("Unable to allocate memory for a vector.");
    return v - nl;
}


static float **
matrix (int nrl, int nrh, int ncl, int nch)

/* Allocates a float matrix with range [nrl..nrh][ncl..nch] */
{
    int i;
    float **m;

    /* allocate pointers to rows */
    MALLOCARRAY(m, (unsigned) (nrh - nrl + 1));
    if (m == NULL)
        pm_error("Unable to allocate memory for a matrix.");

    m -= ncl;

    /* allocate rows and set pointers to them */
    for (i = nrl; i <= nrh; i++)
    {
        MALLOCARRAY(m[i], (unsigned) (nch - ncl + 1));
        if (m[i] == NULL)
            pm_error("Unable to allocate memory for a matrix row.");
        m[i] -= ncl;
    }
    /* return pointer to array of pointers to rows */
    return m;
}

static void 
results (const char * const c, const float * const a)
{
    int i;

    DOT;
    fprintf (stdout, "%s", c);
    for (i = 0; i < 4; ++i)
        fprintf (stdout, "% 1.3e ", a[i]);
    fprintf (stdout, "% 1.3e\n", (a[0] + a[1] + a[2] + a[3]) / 4);
}

static void 
simplesrt (int n, float arr[])
{
    int i, j;
    float a;

    for (j = 2; j <= n; j++)
    {
        a = arr[j];
        i = j - 1;
        while (i > 0 && arr[i] > a)
        {
            arr[i + 1] = arr[i];
            i--;
        }
        arr[i + 1] = a;
    }
}

static void 
mkbalanced (float **a, int n)
{
    int last, j, i;
    float s, r, g, f, c, sqrdx;

    sqrdx = RADIX * RADIX;
    last = 0;
    while (last == 0)
    {
        last = 1;
        for (i = 1; i <= n; i++)
        {
            r = c = 0.0;
            for (j = 1; j <= n; j++)
                if (j != i)
                {
                    c += fabs (a[j][i]);
                    r += fabs (a[i][j]);
                }
            if (c && r)
            {
                g = r / RADIX;
                f = 1.0;
                s = c + r;
                while (c < g)
                {
                    f *= RADIX;
                    c *= sqrdx;
                }
                g = r * RADIX;
                while (c > g)
                {
                    f /= RADIX;
                    c /= sqrdx;
                }
                if ((c + r) / f < 0.95 * s)
                {
                    last = 0;
                    g = 1.0 / f;
                    for (j = 1; j <= n; j++)
                        a[i][j] *= g;
                    for (j = 1; j <= n; j++)
                        a[j][i] *= f;
                }
            }
        }
    }
}


static void 
reduction (float **a, int n)
{
    int m, j, i;
    float y, x;

    for (m = 2; m < n; m++)
    {
        x = 0.0;
        i = m;
        for (j = m; j <= n; j++)
        {
            if (fabs (a[j][m - 1]) > fabs (x))
            {
                x = a[j][m - 1];
                i = j;
            }
        }
        if (i != m)
        {
            for (j = m - 1; j <= n; j++)
                SWAP (a[i][j], a[m][j])  
                    for (j = 1; j <= n; j++)
                        SWAP (a[j][i], a[j][m]) 
                            a[j][i] = a[j][i];
        }
        if (x)
        {
            for (i = m + 1; i <= n; i++)
            {
                if ((y = a[i][m - 1]))
                {
                    y /= x;
                    a[i][m - 1] = y;
                    for (j = m; j <= n; j++)
                        a[i][j] -= y * a[m][j];
                    for (j = 1; j <= n; j++)
                        a[j][m] += y * a[j][i];
                }
            }
        }
    }
}



static void 
hessenberg (float **a, int n, float wr[], float wi[])

{
    int nn, m, l, k, j, its, i, mmin;
    float z, y, x, w, v, u, t, s, r, q, p, anorm;

    anorm = fabs (a[1][1]);
    for (i = 2; i <= n; i++)
        for (j = (i - 1); j <= n; j++)
            anorm += fabs (a[i][j]);
    nn = n;
    t = 0.0;
    while (nn >= 1)
    {
        its = 0;
        do
        {
            for (l = nn; l >= 2; l--)
            {
                s = fabs (a[l - 1][l - 1]) + fabs (a[l][l]);
                if (s == 0.0)
                    s = anorm;
                if ((float) (fabs (a[l][l - 1]) + s) == s)
                    break;
            }
            x = a[nn][nn];
            if (l == nn)
            {
                wr[nn] = x + t;
                wi[nn--] = 0.0;
            }
            else
            {
                y = a[nn - 1][nn - 1];
                w = a[nn][nn - 1] * a[nn - 1][nn];
                if (l == (nn - 1))
                {
                    p = 0.5 * (y - x);
                    q = p * p + w;
                    z = sqrt (fabs (q));
                    x += t;
                    if (q >= 0.0)
                    {
                        z = p + SIGN (z, p); 
                        wr[nn - 1] = wr[nn] = x + z;
                        if (z)
                            wr[nn] = x - w / z;
                        wi[nn - 1] = wi[nn] = 0.0;
                    }
                    else
                    {
                        wr[nn - 1] = wr[nn] = x + p;
                        wi[nn - 1] = -(wi[nn] = z);
                    }
                    nn -= 2;
                }
                else
                {
                    if (its == 30)
                        pm_error("Too many iterations to required "
                                 "to find %s.  Giving up", F14);
                    if (its == 10 || its == 20)
                    {
                        t += x;
                        for (i = 1; i <= nn; i++)
                            a[i][i] -= x;
                        s = fabs (a[nn][nn - 1]) + fabs (a[nn - 1][nn - 2]);
                        y = x = 0.75 * s;
                        w = -0.4375 * s * s;
                    }
                    ++its;
                    for (m = (nn - 2); m >= l; m--)
                    {
                        z = a[m][m];
                        r = x - z;
                        s = y - z;
                        p = (r * s - w) / a[m + 1][m] + a[m][m + 1];
                        q = a[m + 1][m + 1] - z - r - s;
                        r = a[m + 2][m + 1];
                        s = fabs (p) + fabs (q) + fabs (r);
                        p /= s;
                        q /= s;
                        r /= s;
                        if (m == l)
                            break;
                        u = fabs (a[m][m - 1]) * (fabs (q) + fabs (r));
                        v = fabs (p) * (fabs (a[m - 1][m - 1]) + fabs (z) + 
                                        fabs (a[m + 1][m + 1]));
                        if ((float) (u + v) == v)
                            break;
                    }
                    for (i = m + 2; i <= nn; i++)
                    {
                        a[i][i - 2] = 0.0;
                        if (i != (m + 2))
                            a[i][i - 3] = 0.0;
                    }
                    for (k = m; k <= nn - 1; k++)
                    {
                        if (k != m)
                        {
                            p = a[k][k - 1];
                            q = a[k + 1][k - 1];
                            r = 0.0;
                            if (k != (nn - 1))
                                r = a[k + 2][k - 1];
                            if ((x = fabs (p) + fabs (q) + fabs (r)))
                            {
                                p /= x;
                                q /= x;
                                r /= x;
                            }
                        }
                        if ((s = SIGN (sqrt (p * p + q * q + r * r), p))) 
                        {
                            if (k == m)
                            {
                                if (l != m)
                                    a[k][k - 1] = -a[k][k - 1];
                            }
                            else
                                a[k][k - 1] = -s * x;
                            p += s;
                            x = p / s;
                            y = q / s;
                            z = r / s;
                            q /= p;
                            r /= p;
                            for (j = k; j <= nn; j++)
                            {
                                p = a[k][j] + q * a[k + 1][j];
                                if (k != (nn - 1))
                                {
                                    p += r * a[k + 2][j];
                                    a[k + 2][j] -= p * z;
                                }
                                a[k + 1][j] -= p * y;
                                a[k][j] -= p * x;
                            }
                            mmin = nn < k + 3 ? nn : k + 3;
                            for (i = l; i <= mmin; i++)
                            {
                                p = x * a[i][k] + y * a[i][k + 1];
                                if (k != (nn - 1))
                                {
                                    p += z * a[i][k + 2];
                                    a[i][k + 2] -= p * r;
                                }
                                a[i][k + 1] -= p * q;
                                a[i][k] -= p;
                            }
                        }
                    }
                }
            }
        } while (l < nn - 1);
    }
}



static float 
f1_asm (float **P, int Ng)

/* Angular Second Moment */
{
    int i, j;
    float sum = 0;

    for (i = 0; i < Ng; ++i)
        for (j = 0; j < Ng; ++j)
            sum += P[i][j] * P[i][j];

    return sum;

    /*
     * The angular second-moment feature (ASM) f1 is a measure of homogeneity
     * of the image. In a homogeneous image, there are very few dominant
     * gray-tone transitions. Hence the P matrix for such an image will have
     * fewer entries of large magnitude.
     */
}


static float 
f2_contrast (float **P, int Ng)

/* Contrast */
{
    int i, j, n;
    float sum = 0, bigsum = 0;

    for (n = 0; n < Ng; ++n)
    {
        for (i = 0; i < Ng; ++i)
            for (j = 0; j < Ng; ++j)
                if ((i - j) == n || (j - i) == n)
                    sum += P[i][j];
        bigsum += n * n * sum;

        sum = 0;
    }
    return bigsum;

    /*
     * The contrast feature is a difference moment of the P matrix and is a
     * measure of the contrast or the amount of local variations present in an
     * image.
     */
}

static float 
f3_corr (float **P, int Ng)

/* Correlation */
{
    int i, j;
    float sum_sqrx = 0, sum_sqry = 0, tmp, *px;
    float meanx =0 , meany = 0 , stddevx, stddevy;

    px = vector (0, Ng);
    for (i = 0; i < Ng; ++i)
        px[i] = 0;

    /*
     * px[i] is the (i-1)th entry in the marginal probability matrix obtained
     * by summing the rows of p[i][j]
     */
    for (i = 0; i < Ng; ++i)
        for (j = 0; j < Ng; ++j)
            px[i] += P[i][j];


    /* Now calculate the means and standard deviations of px and py */
    /*- fix supplied by J. Michael Christensen, 21 Jun 1991 */
    /*- further modified by James Darrell McCauley, 16 Aug 1991 
     *     after realizing that meanx=meany and stddevx=stddevy
     */
    for (i = 0; i < Ng; ++i)
    {
        meanx += px[i]*i;
        sum_sqrx += px[i]*i*i;
    }
    meany = meanx;
    sum_sqry = sum_sqrx;
    stddevx = sqrt (sum_sqrx - (meanx * meanx));
    stddevy = stddevx;

    /* Finally, the correlation ... */
    for (tmp = 0, i = 0; i < Ng; ++i)
        for (j = 0; j < Ng; ++j)
            tmp += i*j*P[i][j];

    return (tmp - meanx * meany) / (stddevx * stddevy);
    /*
     * This correlation feature is a measure of gray-tone linear-dependencies
     * in the image.
     */
}


static float 
f4_var (float **P, int Ng)

/* Sum of Squares: Variance */
{
    int i, j;
    float mean = 0, var = 0;

    /*- Corrected by James Darrell McCauley, 16 Aug 1991
     *  calculates the mean intensity level instead of the mean of
     *  cooccurrence matrix elements 
     */
    for (i = 0; i < Ng; ++i)
        for (j = 0; j < Ng; ++j)
            mean += i * P[i][j];

    for (i = 0; i < Ng; ++i)
        for (j = 0; j < Ng; ++j)
            var += (i + 1 - mean) * (i + 1 - mean) * P[i][j];

    return var;
}

static float 
f5_idm (float **P, int Ng)

/* Inverse Difference Moment */
{
    int i, j;
    float idm = 0;

    for (i = 0; i < Ng; ++i)
        for (j = 0; j < Ng; ++j)
            idm += P[i][j] / (1 + (i - j) * (i - j));

    return idm;
}

static float 
Pxpy[2 * PGM_MAXMAXVAL];

static float 
f6_savg (float **P, int Ng)

/* Sum Average */
{
    int i, j;
    float savg = 0;

    for (i = 0; i <= 2 * Ng; ++i)
        Pxpy[i] = 0;

    for (i = 0; i < Ng; ++i)
        for (j = 0; j < Ng; ++j)
            Pxpy[i + j + 2] += P[i][j];
    for (i = 2; i <= 2 * Ng; ++i)
        savg += i * Pxpy[i];

    return savg;
}


static float 
f7_svar (float **P, int Ng, float S) {
/* Sum Variance */
    int i, j;
    float var = 0;

    for (i = 0; i <= 2 * Ng; ++i)
        Pxpy[i] = 0;

    for (i = 0; i < Ng; ++i)
        for (j = 0; j < Ng; ++j)
            Pxpy[i + j + 2] += P[i][j];

    for (i = 2; i <= 2 * Ng; ++i)
        var += (i - S) * (i - S) * Pxpy[i];

    return var;
}

static float 
f8_sentropy (float **P, int Ng)

/* Sum Entropy */
{
    int i, j;
    float sentropy = 0;

    for (i = 0; i <= 2 * Ng; ++i)
        Pxpy[i] = 0;

    for (i = 0; i < Ng; ++i)
        for (j = 0; j < Ng; ++j)
            Pxpy[i + j + 2] += P[i][j];

    for (i = 2; i <= 2 * Ng; ++i)
        sentropy -= Pxpy[i] * log10 (Pxpy[i] + EPSILON);

    return sentropy;
}


static float 
f9_entropy (float **P, int Ng)

/* Entropy */
{
    int i, j;
    float entropy = 0;

    for (i = 0; i < Ng; ++i)
        for (j = 0; j < Ng; ++j)
            entropy += P[i][j] * log10 (P[i][j] + EPSILON);

    return -entropy;
}


static float 
f10_dvar (float **P, int Ng)

/* Difference Variance */
{
    int i, j, tmp;
    float sum = 0, sum_sqr = 0, var = 0;

    for (i = 0; i <= 2 * Ng; ++i)
        Pxpy[i] = 0;

    for (i = 0; i < Ng; ++i)
        for (j = 0; j < Ng; ++j)
            Pxpy[abs (i - j)] += P[i][j];

    /* Now calculate the variance of Pxpy (Px-y) */
    for (i = 0; i < Ng; ++i)
    {
        sum += Pxpy[i];
        sum_sqr += Pxpy[i] * Pxpy[i];
    }
    tmp = Ng * Ng;
    var = ((tmp * sum_sqr) - (sum * sum)) / (tmp * tmp);

    return var;
}

static float 
f11_dentropy (float **P, int Ng)
    
/* Difference Entropy */
{
    int i, j;
    float sum = 0;

    for (i = 0; i <= 2 * Ng; ++i)
        Pxpy[i] = 0;

    for (i = 0; i < Ng; ++i)
        for (j = 0; j < Ng; ++j)
            Pxpy[abs (i - j)] += P[i][j];

    for (i = 0; i < Ng; ++i)
        sum += Pxpy[i] * log10 (Pxpy[i] + EPSILON);

    return -sum;
}

static float 
f12_icorr (float **P, int Ng)

/* Information Measures of Correlation */
{
    int i, j;
    float *px, *py;
    float hx = 0, hy = 0, hxy = 0, hxy1 = 0, hxy2 = 0;

    px = vector (0, Ng);
    py = vector (0, Ng);

    /*
     * px[i] is the (i-1)th entry in the marginal probability matrix obtained
     * by summing the rows of p[i][j]
     */
    for (i = 0; i < Ng; ++i)
    {
        for (j = 0; j < Ng; ++j)
        {
            px[i] += P[i][j];
            py[j] += P[i][j];
        }
    }

    for (i = 0; i < Ng; ++i)
        for (j = 0; j < Ng; ++j)
        {
            hxy1 -= P[i][j] * log10 (px[i] * py[j] + EPSILON);
            hxy2 -= px[i] * py[j] * log10 (px[i] * py[j] + EPSILON);
            hxy -= P[i][j] * log10 (P[i][j] + EPSILON);
        }

    /* Calculate entropies of px and py - is this right? */
    for (i = 0; i < Ng; ++i)
    {
        hx -= px[i] * log10 (px[i] + EPSILON);
        hy -= py[i] * log10 (py[i] + EPSILON);
    }
/*  fprintf(stderr,"hxy1=%f\thxy=%f\thx=%f\thy=%f\n",hxy1,hxy,hx,hy); */
    return ((hxy - hxy1) / (hx > hy ? hx : hy));
}

static float 
f13_icorr (float **P, int Ng)

/* Information Measures of Correlation */
{
    int i, j;
    float *px, *py;
    float hx = 0, hy = 0, hxy = 0, hxy1 = 0, hxy2 = 0;

    px = vector (0, Ng);
    py = vector (0, Ng);

    /*
     * px[i] is the (i-1)th entry in the marginal probability matrix obtained
     * by summing the rows of p[i][j]
     */
    for (i = 0; i < Ng; ++i)
    {
        for (j = 0; j < Ng; ++j)
        {
            px[i] += P[i][j];
            py[j] += P[i][j];
        }
    }

    for (i = 0; i < Ng; ++i)
        for (j = 0; j < Ng; ++j)
        {
            hxy1 -= P[i][j] * log10 (px[i] * py[j] + EPSILON);
            hxy2 -= px[i] * py[j] * log10 (px[i] * py[j] + EPSILON);
            hxy -= P[i][j] * log10 (P[i][j] + EPSILON);
        }

    /* Calculate entropies of px and py */
    for (i = 0; i < Ng; ++i)
    {
        hx -= px[i] * log10 (px[i] + EPSILON);
        hy -= py[i] * log10 (py[i] + EPSILON);
    }
    /* fprintf(stderr,"hx=%f\thxy2=%f\n",hx,hxy2); */
    return (sqrt (fabs (1 - exp (-2.0 * (hxy2 - hxy)))));
}

static float 
f14_maxcorr (float **P, int Ng)

/* Returns the Maximal Correlation Coefficient */
{
    int i, j, k;
    float *px, *py, **Q;
    float *x, *iy, tmp;

    px = vector (0, Ng);
    py = vector (0, Ng);
    Q = matrix (1, Ng + 1, 1, Ng + 1);
    x = vector (1, Ng);
    iy = vector (1, Ng);

    /*
     * px[i] is the (i-1)th entry in the marginal probability matrix obtained
     * by summing the rows of p[i][j]
     */
    for (i = 0; i < Ng; ++i)
    {
        for (j = 0; j < Ng; ++j)
        {
            px[i] += P[i][j];
            py[j] += P[i][j];
        }
    }

    /* Find the Q matrix */
    for (i = 0; i < Ng; ++i)
    {
        for (j = 0; j < Ng; ++j)
        {
            Q[i + 1][j + 1] = 0;
            for (k = 0; k < Ng; ++k)
                Q[i + 1][j + 1] += P[i][k] * P[j][k] / px[i] / py[k];
        }
    }

    /* Balance the matrix */
    mkbalanced (Q, Ng);
    /* Reduction to Hessenberg Form */
    reduction (Q, Ng);
    /* Finding eigenvalue for nonsymetric matrix using QR algorithm */
    hessenberg (Q, Ng, x, iy);
    if (sortit)
        simplesrt(Ng,x);
    /* Returns the sqrt of the second largest eigenvalue of Q */
    for (i = 2, tmp = x[1]; i <= Ng; ++i)
        tmp = (tmp > x[i]) ? tmp : x[i];
    return sqrt (x[Ng - 1]);
}

int
main (int argc, char *argv[]) {
    FILE *ifp;
    register gray **grays;
    int tone[PGM_MAXMAXVAL], R0, R45, R90, angle, d = 1, x, y;
    int argn, rows, cols, row, col;
    int itone, jtone, tones;
    float **P_matrix0, **P_matrix45, **P_matrix90, **P_matrix135;
    float ASM[4], contrast[4], corr[4], var[4], idm[4], savg[4];
    float sentropy[4], svar[4], entropy[4], dvar[4], dentropy[4];
    float icorr[4], maxcorr[4];
    gray maxval;
    const char * const usage = "[-d <d>] [pgmfile]";


    pgm_init( &argc, argv );

    argn = 1;

    /* Check for flags. */
    if ( argn < argc && argv[argn][0] == '-' )
    {
        if ( argv[argn][1] == 'd' )
        {
            ++argn;
            if ( argn == argc || sscanf( argv[argn], "%d", &d ) != 1 )
                pm_usage( usage );
        }
        else
            pm_usage( usage );
        ++argn;
    }

    if ( argn < argc )
    {
        ifp = pm_openr( argv[argn] );
        ++argn;
    }
    else
        ifp = stdin;

    if ( argn != argc )
        pm_usage( usage );

    grays = pgm_readpgm (ifp, &cols, &rows, &maxval);
    pm_close (ifp);

    if (maxval > PGM_MAXMAXVAL) 
        pm_error("The maxval of the image (%d) is too high.  \n"
                 "This program's maximum is %d.", maxval, PGM_MAXMAXVAL);

    /* Determine the number of different gray scales (not maxval) */
    for (row = PGM_MAXMAXVAL; row >= 0; --row)
        tone[row] = -1;
    for (row = rows - 1; row >= 0; --row)
        for (col = 0; col < cols; ++col)
            tone[grays[row][col]] = grays[row][col];
    for (row = PGM_MAXMAXVAL, tones = 0; row >= 0; --row)
        if (tone[row] != -1)
            tones++;
    pm_message("(Image has %d graylevels.)", tones);

    /* Collapse array, taking out all zero values */
    for (row = 0, itone = 0; row <= PGM_MAXMAXVAL; row++)
        if (tone[row] != -1)
            tone[itone++] = tone[row];
    /* Now array contains only the gray levels present (in ascending order) */

    /* Allocate memory for gray-tone spatial dependence matrix */
    P_matrix0 = matrix (0, tones, 0, tones);
    P_matrix45 = matrix (0, tones, 0, tones);
    P_matrix90 = matrix (0, tones, 0, tones);
    P_matrix135 = matrix (0, tones, 0, tones);
    for (row = 0; row < tones; ++row)
        for (col = 0; col < tones; ++col)
        {
            P_matrix0[row][col] = P_matrix45[row][col] = 0;
            P_matrix90[row][col] = P_matrix135[row][col] = 0;
        }

    /* Find gray-tone spatial dependence matrix */
    fprintf (stderr, "(Computing spatial dependence matrix...");
    for (row = 0; row < rows; ++row)
        for (col = 0; col < cols; ++col)
            for (x = 0, angle = 0; angle <= 135; angle += 45)
            {
                while (tone[x] != grays[row][col])
                    x++;
                if (angle == 0 && col + d < cols)
                {
                    y = 0;
                    while (tone[y] != grays[row][col + d])
                        y++;
                    P_matrix0[x][y]++;
                    P_matrix0[y][x]++;
                }
                if (angle == 90 && row + d < rows)
                {
                    y = 0;
                    while (tone[y] != grays[row + d][col])
                        y++;
                    P_matrix90[x][y]++;
                    P_matrix90[y][x]++;
                }
                if (angle == 45 && row + d < rows && col - d >= 0)
                {
                    y = 0;
                    while (tone[y] != grays[row + d][col - d])
                        y++;
                    P_matrix45[x][y]++;
                    P_matrix45[y][x]++;
                }
                if (angle == 135 && row + d < rows && col + d < cols)
                {
                    y = 0;
                    while (tone[y] != grays[row + d][col + d])
                        y++;
                    P_matrix135[x][y]++;
                    P_matrix135[y][x]++;
                }
            }
    /* Gray-tone spatial dependence matrices are complete */

    /* Find normalizing constants */
    R0 = 2 * rows * (cols - d);
    R45 = 2 * (rows - d) * (cols - d);
    R90 = 2 * (rows - d) * cols;

    /* Normalize gray-tone spatial dependence matrix */
    for (itone = 0; itone < tones; ++itone)
        for (jtone = 0; jtone < tones; ++jtone)
        {
            P_matrix0[itone][jtone] /= R0;
            P_matrix45[itone][jtone] /= R45;
            P_matrix90[itone][jtone] /= R90;
            P_matrix135[itone][jtone] /= R45;
        }

    fprintf (stderr, " done.)\n");
    fprintf (stderr, "(Computing textural features");
    fprintf (stdout, "\n");
    DOT;
    fprintf (stdout,
             "%s         0         45         90        135        Avg\n",
             BL);

    ASM[0] = f1_asm (P_matrix0, tones);
    ASM[1] = f1_asm (P_matrix45, tones);
    ASM[2] = f1_asm (P_matrix90, tones);
    ASM[3] = f1_asm (P_matrix135, tones);
    results (F1, ASM);

    contrast[0] = f2_contrast (P_matrix0, tones);
    contrast[1] = f2_contrast (P_matrix45, tones);
    contrast[2] = f2_contrast (P_matrix90, tones);
    contrast[3] = f2_contrast (P_matrix135, tones);
    results (F2, contrast);


    corr[0] = f3_corr (P_matrix0, tones);
    corr[1] = f3_corr (P_matrix45, tones);
    corr[2] = f3_corr (P_matrix90, tones);
    corr[3] = f3_corr (P_matrix135, tones);
    results (F3, corr);

    var[0] = f4_var (P_matrix0, tones);
    var[1] = f4_var (P_matrix45, tones);
    var[2] = f4_var (P_matrix90, tones);
    var[3] = f4_var (P_matrix135, tones);
    results (F4, var);


    idm[0] = f5_idm (P_matrix0, tones);
    idm[1] = f5_idm (P_matrix45, tones);
    idm[2] = f5_idm (P_matrix90, tones);
    idm[3] = f5_idm (P_matrix135, tones);
    results (F5, idm);

    savg[0] = f6_savg (P_matrix0, tones);
    savg[1] = f6_savg (P_matrix45, tones);
    savg[2] = f6_savg (P_matrix90, tones);
    savg[3] = f6_savg (P_matrix135, tones);
    results (F6, savg);

    sentropy[0] = f8_sentropy (P_matrix0, tones);
    sentropy[1] = f8_sentropy (P_matrix45, tones);
    sentropy[2] = f8_sentropy (P_matrix90, tones);
    sentropy[3] = f8_sentropy (P_matrix135, tones);
    svar[0] = f7_svar (P_matrix0, tones, sentropy[0]);
    svar[1] = f7_svar (P_matrix45, tones, sentropy[1]);
    svar[2] = f7_svar (P_matrix90, tones, sentropy[2]);
    svar[3] = f7_svar (P_matrix135, tones, sentropy[3]);
    results (F7, svar);
    results (F8, sentropy);

    entropy[0] = f9_entropy (P_matrix0, tones);
    entropy[1] = f9_entropy (P_matrix45, tones);
    entropy[2] = f9_entropy (P_matrix90, tones);
    entropy[3] = f9_entropy (P_matrix135, tones);
    results (F9, entropy);

    dvar[0] = f10_dvar (P_matrix0, tones);
    dvar[1] = f10_dvar (P_matrix45, tones);
    dvar[2] = f10_dvar (P_matrix90, tones);
    dvar[3] = f10_dvar (P_matrix135, tones);
    results (F10, dvar);

    dentropy[0] = f11_dentropy (P_matrix0, tones);
    dentropy[1] = f11_dentropy (P_matrix45, tones);
    dentropy[2] = f11_dentropy (P_matrix90, tones);
    dentropy[3] = f11_dentropy (P_matrix135, tones);
    results (F11, dentropy);

    icorr[0] = f12_icorr (P_matrix0, tones);
    icorr[1] = f12_icorr (P_matrix45, tones);
    icorr[2] = f12_icorr (P_matrix90, tones);
    icorr[3] = f12_icorr (P_matrix135, tones);
    results (F12, icorr);

    icorr[0] = f13_icorr (P_matrix0, tones);
    icorr[1] = f13_icorr (P_matrix45, tones);
    icorr[2] = f13_icorr (P_matrix90, tones);
    icorr[3] = f13_icorr (P_matrix135, tones);
    results (F13, icorr);

    maxcorr[0] = f14_maxcorr (P_matrix0, tones);
    maxcorr[1] = f14_maxcorr (P_matrix45, tones);
    maxcorr[2] = f14_maxcorr (P_matrix90, tones);
    maxcorr[3] = f14_maxcorr (P_matrix135, tones);
    results (F14, maxcorr);


    fprintf (stderr, " done.)\n");

    return 0;
}
