1 /* SPMG/JPEG-LS IMPLEMENTATION V.2.1
2 =====================================
3 These programs are Copyright (c) University of British Columbia. All rights reserved.
4 They may be freely redistributed in their entirety provided that this copyright
5 notice is not removed. THEY MAY NOT BE SOLD FOR PROFIT OR INCORPORATED IN
6 COMMERCIAL PROGRAMS WITHOUT THE WRITTEN PERMISSION OF THE COPYRIGHT HOLDER.
7 Each program is provided as is, without any express or implied warranty,
8 without even the warranty of fitness for a particular purpose.
10 =========================================================
11 THIS SOFTWARE IS BASED ON HP's implementation of jpeg-ls:
12 =========================================================
14 LOCO-I/JPEG-LS IMPLEMENTATION V.0.90
15 -------------------------------------------------------------------------------
16 (c) COPYRIGHT HEWLETT-PACKARD COMPANY, 1995-1999.
17 HEWLETT-PACKARD COMPANY ("HP") DOES NOT WARRANT THE ACCURACY OR
18 COMPLETENESS OF THE INFORMATION GIVEN HERE. ANY USE MADE OF, OR
19 RELIANCE ON, SUCH INFORMATION IS ENTIRELY AT USER'S OWN RISK.
20 BY DOWNLOADING THE LOCO-I/JPEG-LS COMPRESSORS/DECOMPRESSORS
21 ("THE SOFTWARE") YOU AGREE TO BE BOUND BY THE TERMS AND CONDITIONS
22 OF THIS LICENSING AGREEMENT.
23 YOU MAY DOWNLOAD AND USE THE SOFTWARE FOR NON-COMMERCIAL PURPOSES
24 FREE OF CHARGE OR FURTHER OBLIGATION. YOU MAY NOT, DIRECTLY OR
25 INDIRECTLY, DISTRIBUTE THE SOFTWARE FOR A FEE, INCORPORATE THIS
26 SOFTWARE INTO ANY PRODUCT OFFERED FOR SALE, OR USE THE SOFTWARE
27 TO PROVIDE A SERVICE FOR WHICH A FEE IS CHARGED.
28 YOU MAY MAKE COPIES OF THE SOFTWARE AND DISTRIBUTE SUCH COPIES TO
29 OTHER PERSONS PROVIDED THAT SUCH COPIES ARE ACCOMPANIED BY
30 HEWLETT-PACKARD'S COPYRIGHT NOTICE AND THIS AGREEMENT AND THAT
31 SUCH OTHER PERSONS AGREE TO BE BOUND BY THE TERMS OF THIS AGREEMENT.
32 THE SOFTWARE IS NOT OF PRODUCT QUALITY AND MAY HAVE ERRORS OR DEFECTS.
33 THE JPEG-LS STANDARD IS STILL UNDER DEVELOPMENT. THE SOFTWARE IS NOT A
34 FINAL OR FULL IMPLEMENTATION OF THE STANDARD. HP GIVES NO EXPRESS OR
35 IMPLIED WARRANTY OF ANY KIND AND ANY IMPLIED WARRANTIES OF
36 MERCHANTABILITY AND FITNESS FOR PURPOSE ARE DISCLAIMED.
37 HP SHALL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL,
38 OR CONSEQUENTIAL DAMAGES ARISING OUT OF ANY USE OF THE SOFTWARE.
39 -------------------------------------------------------------------------------
42 /* initialize.c --- functions to initialize look up tables
43 * and statistics tables
45 * Initial code by Alex Jakulin, Aug. 1995
47 * Modified and optimized: Gadiel Seroussi, October 1995
50 * Modified and added Restart marker and input tables by:
51 * David Cheng-Hsiu Chu, and Ismail R. Ismail march 1999
62 int vLUT[3][2 * LUTMAX16];
64 int classmap[CONTEXTS1];
66 int *qdiv0, *qdiv, /* quantization table (division via look-up) */
67 *qmul0, *qmul; /* dequantization table */
76 /* Setup Look Up Tables for quantized gradient merging */
82 lmax = min(alpha,lutmax);
84 /* implementation limitation: */
86 fprintf(stderr,"Sorry, current implementation does not support threshold T3 > %d, got %d\n",lmax-1,T3);
91 /* Build classification tables (lossless or lossy) */
95 for (i = -lmax + 1; i < lmax; i++) {
97 if ( i <= -T3 ) /* ...... -T3 */
99 else if ( i <= -T2 ) /* -(T3-1) ... -T2 */
101 else if ( i <= -T1 ) /* -(T2-1) ... -T1 */
104 else if ( i <= -1 ) /* -(T1-1) ... -1 */
106 else if ( i == 0 ) /* just 0 */
109 else if ( i < T1 ) /* 1 ... T1-1 */
111 else if ( i < T2 ) /* T1 ... T2-1 */
113 else if ( i < T3 ) /* T2 ... T3-1 */
118 vLUT[0][i + lutmax] = CREGIONS * CREGIONS * idx;
119 vLUT[1][i + lutmax] = CREGIONS * idx;
120 vLUT[2][i + lutmax] = idx;
125 for (i = -lmax + 1; i < lmax; i++) {
127 if ( NEAR >= (alpha-1) )
128 idx = 0; /* degenerate case, regardless of thresholds */
131 if ( i <= -T3 ) /* ...... -T3 */
133 else if ( i <= -T2 ) /* -(T3-1) ... -T2 */
135 else if ( i <= -T1 ) /* -(T2-1) ... -T1 */
138 else if ( i <= -NEAR-1 ) /* -(T1-1) ... -NEAR-1 */
140 else if ( i <= NEAR ) /* within NEAR of 0 */
143 else if ( i < T1 ) /* 1 ... T1-1 */
145 else if ( i < T2 ) /* T1 ... T2-1 */
147 else if ( i < T3 ) /* T2 ... T3-1 */
152 vLUT[0][i + lutmax] = CREGIONS * CREGIONS * idx;
153 vLUT[1][i + lutmax] = CREGIONS * idx;
154 vLUT[2][i + lutmax] = idx;
160 /* prepare context mapping table (symmetric context merging) */
162 for ( i=1, j=0; i<CONTEXTS1; i++) {
163 int q1, q2, q3, n1=0, n2=0, n3=0, ineg, sgn;
168 q1 = i/(CREGIONS*CREGIONS); /* first digit */
169 q2 = (i/CREGIONS)%CREGIONS; /* second digit */
170 q3 = i%CREGIONS; /* third digit */
172 if((q1%2)||(q1==0 && (q2%2))||(q1==0 && q2==0 && (q3%2)))
177 /* compute negative context */
178 if(q1) n1 = q1 + ((q1%2) ? 1 : -1);
179 if(q2) n2 = q2 + ((q2%2) ? 1 : -1);
180 if(q3) n3 = q3 + ((q3%2) ? 1 : -1);
182 ineg = (n1*CREGIONS+n2)*CREGIONS+n3;
183 j++ ; /* next class number */
185 classmap[ineg] = -sgn*j;
196 /* prepare quantization tables for near-lossless quantization */
197 void prepare_qtables(int absize, int NEAR)
205 if ( (qdiv0 = (int *)calloc(2*absize-1,sizeof(int)))==NULL ) {
206 perror("qdiv table");
209 qdiv = qdiv0+absize-1;
211 if ( (qmul0 = (int *)calloc(2*beta-1,sizeof(int)))==NULL ) {
212 perror("qmul table");
217 for ( diff = -(absize-1); diff<absize; diff++ ) {
219 qdiff = - ( (NEAR-diff)/quant );
221 qdiff = ( NEAR + diff )/quant;
224 for ( qdiff = -(beta-1); qdiff<beta; qdiff++ ) {
233 /* Initialize A[], B[], C[], and N[] arrays */
234 void init_stats(int absize)
237 int i, initabstat, slack;
239 slack = 1<<INITABSLACK;
240 initabstat = (absize + slack/2)/slack;
241 if ( initabstat < MIN_INITABSTAT ) initabstat = MIN_INITABSTAT;
243 /* do the statistics initialization */
244 for (i = 0; i < TOT_CONTEXTS; ++i) {