s += abs(pix1[13] - avg4(pix2[13], pix2[14], pix3[13], pix3[14]));
s += abs(pix1[14] - avg4(pix2[14], pix2[15], pix3[14], pix3[15]));
s += abs(pix1[15] - avg4(pix2[15], pix2[16], pix3[15], pix3[16]));
s += abs(pix1[13] - avg4(pix2[13], pix2[14], pix3[13], pix3[14]));
s += abs(pix1[14] - avg4(pix2[14], pix2[15], pix3[14], pix3[15]));
s += abs(pix1[15] - avg4(pix2[15], pix2[16], pix3[15], pix3[16]));