diff options
Diffstat (limited to 'kernel/kls_ljpeg/ljpeg2ppm/predictor.h')
| -rw-r--r-- | kernel/kls_ljpeg/ljpeg2ppm/predictor.h | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/kernel/kls_ljpeg/ljpeg2ppm/predictor.h b/kernel/kls_ljpeg/ljpeg2ppm/predictor.h new file mode 100644 index 0000000..a27b34e --- /dev/null +++ b/kernel/kls_ljpeg/ljpeg2ppm/predictor.h @@ -0,0 +1,176 @@ +/* + * predictor.h -- + * + * Code for predictor calculation. Its function version, predictor.c, + * is used in debugging compilation. + * + * Copyright (c) 1994 Kongji Huang and Brian C. Smith. + * Cornell University + * 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 CORNELL UNIVERSITY 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 CORNELL + * UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * CORNELL UNIVERSITY 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 CORNELL UNIVERSITY HAS NO OBLIGATION TO + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + */ + +#ifndef _PREDICTOR +#define _PREDICTOR + +#ifndef DEBUG + +/* + *-------------------------------------------------------------- + * + * Predict -- + * + * Calculate the predictor for pixel[row][col][curComp], + * i.e. curRowBuf[col][curComp]. It handles the all special + * cases at image edges, such as first row and first column + * of a scan. + * + * Results: + * predictor is passed out. + * + * Side effects: + * None. + * + *-------------------------------------------------------------- + */ +#define Predict(row,col,curComp,curRowBuf,prevRowBuf,Pr,Pt,psv,predictor)\ +{ register int left,upper,diag,leftcol; \ + \ + leftcol=col-1; \ + if (row==0) { \ + \ + /* \ + * The predictor of first pixel is (1<<(Pr-Pt-1), and the \ + * predictors for rest of first row are left neighbors. \ + */ \ + if (col==0) { \ + *predictor = (1<<(Pr-Pt-1)); \ + } \ + else { \ + *predictor = curRowBuf[leftcol][curComp]; \ + } \ + } \ + else { \ + \ + /* \ + * The predictors of first column are upper neighbors. \ + * All other preditors are calculated according to psv. \ + */ \ + upper=prevRowBuf[col][curComp]; \ + if (col==0) \ + *predictor = upper; \ + else { \ + left=curRowBuf[leftcol][curComp]; \ + diag=prevRowBuf[leftcol][curComp]; \ + switch (psv) { \ + case 0: \ + *predictor = 0; \ + break; \ + case 1: \ + *predictor = left; \ + break; \ + case 2: \ + *predictor = upper; \ + break; \ + case 3: \ + *predictor = diag; \ + break; \ + case 4: \ + *predictor = left+upper-diag; \ + break; \ + case 5: \ + *predictor = left+((upper-diag)>>1); \ + break; \ + case 6: \ + *predictor = upper+((left-diag)>>1); \ + break; \ + case 7: \ + *predictor = (left+upper)>>1; \ + break; \ + default: \ + fprintf(stderr,"Warning: Undefined PSV\n"); \ + *predictor = 0; \ + } \ + } \ + } \ +} + +/* + *-------------------------------------------------------------- + * + * QuickPredict -- + * + * Calculate the predictor for sample curRowBuf[col][curComp]. + * It does not handle the special cases at image edges, such + * as first row and first column of a scan. We put the special + * case checkings outside so that the computations in main + * loop can be simpler. This has enhenced the performance + * significantly. + * + * Results: + * predictor is passed out. + * + * Side effects: + * None. + * + *-------------------------------------------------------------- + */ +#define QuickPredict(col,curComp,curRowBuf,prevRowBuf,psv,predictor){ \ + register int left,upper,diag,leftcol; \ + \ + leftcol=col-1; \ + upper=prevRowBuf[col][curComp]; \ + left=curRowBuf[leftcol][curComp]; \ + diag=prevRowBuf[leftcol][curComp]; \ + \ + /* \ + * All predictor are calculated according to psv. \ + */ \ + switch (psv) { \ + case 0: \ + *predictor = 0; \ + break; \ + case 1: \ + *predictor = left; \ + break; \ + case 2: \ + *predictor = upper; \ + break; \ + case 3: \ + *predictor = diag; \ + break; \ + case 4: \ + *predictor = left+upper-diag; \ + break; \ + case 5: \ + *predictor = left+((upper-diag)>>1); \ + break; \ + case 6: \ + *predictor = upper+((left-diag)>>1); \ + break; \ + case 7: \ + *predictor = (left+upper)>>1; \ + break; \ + default: \ + fprintf(stderr,"Warning: Undefined PSV\n"); \ + *predictor = 0; \ + } \ +} + +#endif /* DEBUG */ +#endif /* _PREDICTOR */ |