/* * ordered2.c -- * *      This file contains C code to implement a faster ordered dither *      than the one found in ordered.c.  This dither is the default *      if no dither is specified. * *//*   * Copyright (c) 1995 The Regents of the University of California. * All rights reserved. *  * Permission to use, copy, modify, and distribute this software and its * documentation for any purpose, without fee, and without written agreement is * hereby granted, provided that the above copyright notice and the following * two paragraphs appear in all copies of this software. *  * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT * OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF * CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. *  * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS * ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. */#include "video.h"#include "proto.h"#include "dither.h"#define DITH_SIZE 16/* Structures used to implement hybrid ordered dither/floyd-steinberg   dither algorithm.*/static unsigned char ***ditherPtr[DITH_SIZE];/* *-------------------------------------------------------------- * *  InitOrderedDither-- * *	Structures intialized for ordered dithering.  * * Results: *	None. * * Side effects: *      None. * *-------------------------------------------------------------- */voidInitOrdered2Dither(){  unsigned char ****pos_2_cb;  unsigned char ***cb_2_cr;  unsigned char **cr_2_l;  int cb_val, cb_rval, cr_val, cr_rval, l_val, l_rval;  int i, j, pos;  int err_range, threshval;  pos_2_cb = (unsigned char ****) malloc (DITH_SIZE*sizeof(unsigned char ***));  cb_2_cr = (unsigned char ***) malloc(CB_RANGE*sizeof(unsigned char **));  cr_2_l = (unsigned char **) malloc(CR_RANGE*sizeof(unsigned char *));  for (pos=0; pos<DITH_SIZE; pos++) {        pos_2_cb[pos] = (unsigned char ***) malloc(256*(sizeof(unsigned char **)));    for (j=0; j<CB_RANGE; j++) {      cb_2_cr[j] = (unsigned char **) malloc(256*(sizeof(unsigned char *)));    }    for (cb_val=0; cb_val<cb_values[0]; cb_val++) {      (pos_2_cb[pos])[cb_val] = cb_2_cr[0];    }    for (cb_rval=0; cb_rval<(CB_RANGE-1); cb_rval++) {      err_range = cb_values[cb_rval+1] - cb_values[cb_rval];      threshval = ((pos*err_range)/DITH_SIZE)+cb_values[cb_rval];      for (cb_val=cb_values[cb_rval]; cb_val<cb_values[cb_rval+1]; cb_val++) {	if (cb_val>threshval) (pos_2_cb[pos])[cb_val] = cb_2_cr[cb_rval+1];	else (pos_2_cb[pos])[cb_val] = cb_2_cr[cb_rval];      }    }    for (cb_val=cb_values[CB_RANGE-1]; cb_val<256; cb_val++) {      (pos_2_cb[pos])[cb_val] = cb_2_cr[CB_RANGE-1];    }    for (cb_rval=0; cb_rval<CB_RANGE; cb_rval++) {            for (j=0; j<CR_RANGE; j++) {	cr_2_l[j] = (unsigned char *) malloc(256*(sizeof(unsigned char)));      }      for (cr_val=0; cr_val < cr_values[0]; cr_val++) {	(cb_2_cr[cb_rval])[cr_val] = cr_2_l[0];      }      for (cr_rval=0; cr_rval<(CR_RANGE-1); cr_rval++) {	err_range = cr_values[cr_rval+1] - cr_values[cr_rval];	threshval = ((pos*err_range)/DITH_SIZE)+cr_values[cr_rval];		for (cr_val=cr_values[cr_rval]; cr_val<cr_values[cr_rval+1]; cr_val++) {	  if (cr_val>threshval) (cb_2_cr[cb_rval])[cr_val] = cr_2_l[cr_rval+1];	  else (cb_2_cr[cb_rval])[cr_val] = cr_2_l[cr_rval];	}      }            for (cr_val=cr_values[CR_RANGE-1]; cr_val<256; cr_val++) {	(cb_2_cr[cb_rval])[cr_val] = cr_2_l[CR_RANGE-1];      }            for (cr_rval=0; cr_rval<CR_RANGE; cr_rval++) {		for (l_val = 0; l_val < lum_values[0]; l_val++) {	  (cr_2_l[cr_rval])[l_val] = pixel[cb_rval+(cr_rval*CB_RANGE)+					    (0*CR_RANGE*CB_RANGE)];	}	for (l_rval=0; l_rval<(LUM_RANGE-1); l_rval++) {	  err_range = lum_values[l_rval+1] - lum_values[l_rval];	  threshval = ((pos*err_range) /DITH_SIZE) + lum_values[l_rval];	  for (l_val = lum_values[l_rval]; l_val < lum_values[l_rval+1]; l_val++) {	    if (l_val>threshval) (cr_2_l[cr_rval])[l_val] = 	      pixel[cb_rval+(cr_rval*CB_RANGE)+((l_rval+1)*CR_RANGE*CB_RANGE)];	    else (cr_2_l[cr_rval])[l_val] =	      pixel[cb_rval+(cr_rval*CB_RANGE)+(l_rval*CR_RANGE*CB_RANGE)];	  }	}	for (l_val = lum_values[LUM_RANGE-1]; l_val < 256; l_val++) {	  (cr_2_l[cr_rval])[l_val] = 	    pixel[cb_rval+(cr_rval*CB_RANGE)+((LUM_RANGE-1)*CR_RANGE*CB_RANGE)];	}      }    }  }  for (i=0; i<DITH_SIZE; i++) {    ditherPtr[i] = pos_2_cb[i];  }}/* *-------------------------------------------------------------- * * Ordered2DitherImage -- * *	Dithers an image using an ordered dither. *	Assumptions made: *	  1) The color space is allocated y:cr:cb = 8:4:4 *	  2) The spatial resolution of y:cr:cb is 4:1:1 *      The channels are dithered based on the standard *      ordered dither pattern for a 4x4 area.  * * Results: *	None. * * Side effects: *	None. * *-------------------------------------------------------------- */voidOrdered2DitherImage (lum, cr, cb, out, h, w)    unsigned char *lum;    unsigned char *cr;    unsigned char *cb;    unsigned char *out;    int w, h;{  unsigned char *l, *r, *b, *o1, *o2;  unsigned char *l2;  unsigned char L, R, B;  int i, j;  unsigned char ***dp0 = ditherPtr[0];  unsigned char ***dp2 = ditherPtr[2];  unsigned char ***dp4 = ditherPtr[4];  unsigned char ***dp6 = ditherPtr[6];  unsigned char ***dp8 = ditherPtr[8];  unsigned char ***dp10 = ditherPtr[10];  unsigned char ***dp12 = ditherPtr[12];  unsigned char ***dp14 = ditherPtr[14];  unsigned char ***dp1 = ditherPtr[1];  unsigned char ***dp3 = ditherPtr[3];  unsigned char ***dp5 = ditherPtr[5];  unsigned char ***dp7 = ditherPtr[7];  unsigned char ***dp9 = ditherPtr[9];  unsigned char ***dp11 = ditherPtr[11];  unsigned char ***dp13 = ditherPtr[13];  unsigned char ***dp15 = ditherPtr[15];  l = lum;  l2 = lum+w;  r = cr;  b = cb;  o1 = out;  o2 = out+w;  for (i=0; i<h; i+=4) {    for (j=0; j<w; j+=8) {      R = r[0]; B = b[0];      L = l[0];      o1[0] = ((dp0[B])[R])[L];      L = l[1];      o1[1] = ((dp8[B])[R])[L];      L = l2[0];      o2[0] = ((dp12[B])[R])[L];      L = l2[1];      o2[1] = ((dp4[B])[R])[L];      R = r[1]; B = b[1];      L = l[2];      o1[2] = ((dp2[B])[R])[L];      L = l[3];      o1[3] = ((dp10[B])[R])[L];      L = l2[2];      o2[2] = ((dp14[B])[R])[L];      L = l2[3];      o2[3] = ((dp6[B])[R])[L];      R = r[2]; B = b[2];      L = l[4];      o1[4] = ((dp0[B])[R])[L];      L = l[5];      o1[5] = ((dp8[B])[R])[L];      L = l2[4];      o2[4] = ((dp12[B])[R])[L];      L = l2[5];      o2[5] = ((dp4[B])[R])[L];      R = r[3]; B = b[3];      L = l[6];      o1[6] = ((dp2[B])[R])[L];      L = l[7];      o1[7] = ((dp10[B])[R])[L];      L = l2[6];      o2[6] = ((dp14[B])[R])[L];      L = l2[7];      o2[7] = ((dp6[B])[R])[L];      l += 8;      l2 += 8;      r += 4;      b += 4;      o1 += 8;      o2 += 8;    }    l += w; 	l2 += w;    o1 += w; 	o2 += w;    for (j=0; j<w; j+=8) {      R = r[0]; B = b[0];      L = l[0];      o1[0] = ((dp3[B])[R])[L];      L = l[1];      o1[1] = ((dp11[B])[R])[L];      L = l2[0];      o2[0] = ((dp15[B])[R])[L];      L = l2[1];      o2[1] = ((dp7[B])[R])[L];      R = r[1]; B = b[1];      L = l[2];      o1[2] = ((dp1[B])[R])[L];      L = l[3];      o1[3] = ((dp9[B])[R])[L];      L = l2[2];      o2[2] = ((dp13[B])[R])[L];      L = l2[3];      o2[3] = ((dp5[B])[R])[L];      R = r[2]; B = b[2];      L = l[4];      o1[4] = ((dp3[B])[R])[L];      L = l[5];      o1[5] = ((dp11[B])[R])[L];      L = l2[4];      o2[4] = ((dp15[B])[R])[L];      L = l2[5];      o2[5] = ((dp7[B])[R])[L];      R = r[3]; B = b[3];      L = l[6];      o1[6] = ((dp1[B])[R])[L];      L = l[7];      o1[7] = ((dp9[B])[R])[L];      L = l2[6];      o2[6] = ((dp13[B])[R])[L];      L = l2[7];      o2[7] = ((dp5[B])[R])[L];      l += 8;      l2 += 8;      r += 4;      b += 4;      o1 += 8;      o2 += 8;    }    l += w; 	l2 += w;    o1 += w;	o2 += w;  }}