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sector8.c

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#include "sadie.h"
#include "proto.h"

/*----------------------------------------------------------------------------*/
/*-General Information--------------------------------------------------------*/
/*                                                                            */
/*   This function calculates the sector of an angle as shown:                */
/*                                                                            */
/*          0     -  22.5 degrees   --      Sector 0                          */
/*          22.5  -  45.0 degrees   --      Sector 1                          */
/*          45.0  -  67.5 degrees   --      Sector 2                          */
/*          67.5  -  90.0 degrees   --      Sector 3                          */
/*          90.0  - 112.5 degrees   --      Sector 4                          */
/*          112.5 - 135.0 degrees   --      Sector 5                          */
/*          135.0 - 157.5 degrees   --      Sector 6                          */
/*          157.5 - 180.0 degrees   --      Sector 7                          */
/*          180.0 - 202.5 degrees   --      Sector 0                          */
/*          202.5 - 225.0 degrees   --      Sector 1                          */
/*          225.0 - 247.5 degrees   --      Sector 2                          */
/*          247.5 - 270.0 degrees   --      Sector 3                          */
/*          270.0 - 292.5 degrees   --      Sector 4                          */
/*          292.5 - 315.0 degrees   --      Sector 5                          */
/*          315.0 - 337.5 degrees   --      Sector 6                          */
/*          337.5 - 360.0 degrees   --      Sector 7                          */
/*                                                                            */
/*                                                                            */
/*----------------------------------------------------------------------------*/
/*-Interface Information------------------------------------------------------*/
void SECTOR8 (
IMAGE  *in,     /*  I   Pointer to the input image.                           */
IMAGE  **out    /*  O   Address of a pointer to the output image.             */
/*----------------------------------------------------------------------------*/
) { register short i, j, k;
    char msg[SLEN];
    double theta;
    int sectornum;

    /* if (TIMES) TIMING(T_SECTOR8); */
    if (NAMES) {
        MESSAGE('I',"");
        MESSAGE('I',"SECTOR8");
        MESSAGE('I',"");
        sprintf(msg," Input image:                       %s",in->text);
        MESSAGE('I',msg);
        MESSAGE('I'," ...............");
    }

    /* check input */
    if (!CHECKIMG(in)) {
        MESSAGE('E'," Can't identify image.");
        goto the_end;
    }
    
    /* Find the min and max values in the image */
    RANGE(in);
    
    /* Verify that this is a gradient direction image */
    if (in->gmin < -2.0*PI  ||  2.0*PI < in->gmax) {
        MESSAGE('E'," This is not a gradient direction image!");
        MESSAGE('E'," Direction must be between -360 and +360 degrees.");
        goto the_end;
    }

    /* create image of appropriate size */
    if (!CHECKIMG(*out)) GETMEM(in->nbnd,in->nlin,in->npix,out);
    if (!*out) goto the_end;



    /* build sector image */
    for (i=0; i<in->nbnd; i++) {
        for (j=0; j<in->nlin; j++) {
            for (k=0; k<in->npix; k++) {
                theta = (double)(in->data[i][j][k]);
                
                /* Convert to positive angle */
                if (theta < 0.0) {
                    theta = (2.0*PI) + theta;
                }

                if (theta < (PI / 8.0)  &&  0 <= theta) {
                    sectornum = 0;
                } else if (theta < ((2.0*PI) / 8.0)  &&  (PI / 8.0) <= theta) {
                    sectornum = 1;
                } else if (theta < ((3.0*PI)/8.0)  &&  ((2.0*PI)/8.0) <= theta) {
                    sectornum = 2;
                } else if (theta < ((4.0*PI)/8.0)  &&  ((3.0*PI)/8.0) <= theta) {
                    sectornum = 3;
                } else if (theta < ((5.0*PI)/8.0)  &&  ((4.0*PI)/8.0) <= theta) {
                    sectornum = 4;
                } else if (theta < ((6.0*PI)/8.0)  &&  ((5.0*PI)/8.0) <= theta) {
                    sectornum = 5;
                } else if (theta < ((7.0*PI)/8.0)  &&  ((6.0*PI)/8.0) <= theta) {
                    sectornum = 6;
                } else if (theta < ((8.0*PI)/8.0)  &&  ((7.0*PI)/8.0) <= theta) {
                    sectornum = 7;
                } else if (theta < ((9.0*PI)/8.0)  &&  ((8.0*PI)/8.0) <= theta) {
                    sectornum = 0;
                } else if (theta < ((10.0*PI)/8.0)  &&  ((9.0*PI)/8.0) <= theta) {
                    sectornum = 1;
                } else if (theta < ((11.0*PI)/8.0)  &&  ((10.0*PI)/8.0) <= theta) {
                    sectornum = 2;
                } else if (theta < ((12.0*PI)/8.0)  &&  ((11.0*PI)/8.0) <= theta) {
                    sectornum = 3;
                } else if (theta < ((13.0*PI)/8.0)  &&  ((12.0*PI)/8.0) <= theta) {
                    sectornum = 4;
                } else if (theta < ((14.0*PI)/8.0)  &&  ((13.0*PI)/8.0) <= theta) {
                    sectornum = 5;
                } else if (theta < ((15.0*PI)/8.0)  &&  ((14.0*PI)/8.0) <= theta) {
                    sectornum = 6;
                } else {  /* if (theta <= (2.0*PI)  &&  ((15.0*PI)/8.0) <= theta) */
                    sectornum = 7;
                }
            
                (*out)->data[i][j][k] = (PIXEL)(sectornum);
            }
        }
    }


        
    the_end:
    /* if (TIMES) TIMING(T_EXIT); */
}

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