Function psl_gray_encode

src/postscriptlight.c:717–729

/* This one is NOT static since needed in psimage, at least for now */

unsigned char *psl_gray_encode (struct PSL_CTRL *PSL, size_t *nbytes, unsigned char *input) {
	/* Recode RGB stream as gray-scale stream */

	size_t in, out, nout;
	unsigned char *output = NULL;

	nout = *nbytes / 3;
	output = PSL_memory (PSL, NULL, nout, unsigned char);

	for (in = out = 0; in < *nbytes; out++, in += 3) output[out] = (char) lrint (PSL_YIQ ((&input[in])));
	*nbytes = nout;
	return (output);
}

/* Define local (static) support functions called inside the public PSL functions */