1 /*--------------------------------------------------------------
2 Signal processing function library libsgp
3 ( Convolution Rev.940809)
4 Written by H.Goto , Aug.1994
5 --------------------------------------------------------------*/
6
7 /*--------------------------------------------------------------------
8 Copyright (C) 1994 Hideaki Goto
9
10 All Rights Reserved
11
12 Permission to use, copy, modify, and distribute this software and
13 its documentation for any purpose is hereby granted without fee,
14 provided that (i) the above copyright notice and this permission
15 notice appear in all copies and in supporting documentation, (ii)
16 the name of the author, Hideaki Goto, may not be used in any
17 advertising or otherwise to promote the sale, use or other
18 dealings in this software without prior written authorization
19 from the author, (iii) this software may not be used for
20 commercial products without prior written permission from the
21 author, and (iv) the notice of the modification is specified in
22 case of that the modified copies of this software are distributed.
23
24 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND.
25 THE AUTHOR WILL NOT BE RESPONSIBLE FOR ANY DAMAGE CAUSED BY THIS
26 SOFTWARE.
27 --------------------------------------------------------------------*/
28
29
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <memory.h>
33
34 #include "sgplib.h"
35
36
37 /*------------------------------------------------------
38 Convolution
39 ------------------------------------------------------*/
40
sgp_convolutec(char * src,char * dst,int len,char sdata,char * mask,char div,int masklen)41 int sgp_convolutec(char *src,char *dst,int len,char sdata, \
42 char *mask,char div,int masklen){
43 char *buf,sum;
44 int i,j,off;
45 off = (masklen -1) /2;
46 if ( NULL == (buf = (char *)malloc(len + masklen)) ) return(-1);
47 for ( i=0 ; i<off ; i++ ) buf[i] = sdata;
48 for ( i=(off + masklen) ; i<(len + masklen) ; i++ ) buf[i] = sdata;
49 memcpy((char *)&buf[off],(char *)src,len * sizeof(char));
50 if ( div == 1 ){
51 for ( i=0 ; i<len ; i++ ){
52 sum = 0;
53 for ( j=0 ; j<masklen ; j++ ) sum += mask[j] * buf[i + j];
54 *dst++ = sum;
55 }
56 }
57 else{ for ( i=0 ; i<len ; i++ ){
58 sum = 0;
59 for ( j=0 ; j<masklen ; j++ ) sum += mask[j] * buf[i + j];
60 *dst++ = sum / div;
61 }
62 }
63 free(buf);
64 return(0);
65 }
66
67
sgp_convolutei(int * src,int * dst,int len,int sdata,int * mask,int div,int masklen)68 int sgp_convolutei(int *src,int *dst,int len,int sdata, \
69 int *mask,int div,int masklen){
70 int *buf,sum;
71 int i,j,off;
72 off = (masklen -1) /2;
73 if ( NULL == (buf = (int *)malloc((len + masklen) * sizeof(int))) ) return(-1);
74 for ( i=0 ; i<off ; i++ ) buf[i] = sdata;
75 for ( i=(off + masklen) ; i<(len + masklen) ; i++ ) buf[i] = sdata;
76 memcpy((char *)&buf[off],(char *)src,len * sizeof(int));
77 if ( div == 1 ){
78 for ( i=0 ; i<len ; i++ ){
79 sum = 0;
80 for ( j=0 ; j<masklen ; j++ ) sum += mask[j] * buf[i + j];
81 *dst++ = sum;
82 }
83 }
84 else{ for ( i=0 ; i<len ; i++ ){
85 sum = 0;
86 for ( j=0 ; j<masklen ; j++ ) sum += mask[j] * buf[i + j];
87 *dst++ = sum / div;
88 }
89 }
90 free(buf);
91 return(0);
92 }
93
94
95