uniform-pattern-lbp.c

// Codes to show the 'uniform pattern' of LBP

#include <stdio.h>

typedef unsigned char uint8_t;

#define BIT_AT(v, pos) (((v) >> (pos)) & 1)

static int
numOfTran(uint8_t v) {
        int n = 0;
        for (int i = 1; i < 8; ++i)
                n += BIT_AT(v, i) != BIT_AT(v, i-1);
        n += BIT_AT(v,0) != BIT_AT(v, 7);
        return n;
}

static void
binaryRep(uint8_t v) {
        char rep[9] = {0};
        // for little endian
        for (int i = 0; i < 8; ++i)
                rep[7-i] = BIT_AT(v, i) + '0';
        puts(rep);
}

static void
test() {
        int cnt = 0;
        for (int i = 0; i < 256; ++i) {
                binaryRep(i);
                int t = numOfTran(i);
                printf("%d\n", t);
                cnt += t <= 2;
        }
        printf("\n%d\n", cnt);
}

int
main(int ac, char **av) {
        test();
        return 0;
}