diff options
Diffstat (limited to 'Modules/imageop.c')
| -rw-r--r-- | Modules/imageop.c | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/Modules/imageop.c b/Modules/imageop.c index c575c25..0f30246 100644 --- a/Modules/imageop.c +++ b/Modules/imageop.c @@ -167,6 +167,88 @@ imageop_grey2mono(self, args) } static object * +imageop_grey2grey4(self, args) + object *self; + object *args; +{ + int x, y, len; + unsigned char *cp, *ncp; + unsigned char ovalue; + object *rv; + int i; + int pos; + + + if ( !getargs(args, "(s#ii)", &cp, &len, &x, &y) ) + return 0; + + if ( x*y != len ) { + err_setstr(ImageopError, "String has incorrect length"); + return 0; + } + + rv = newsizedstringobject(NULL, (len+1)/2); + if ( rv == 0 ) + return 0; + ncp = (unsigned char *)getstringvalue(rv); + pos = 0; + ovalue = 0; + for ( i=0; i < len; i++ ) { + ovalue |= (cp[i] & 0xf0) >> pos; + pos += 4; + if ( pos == 8 ) { + *ncp++ = ovalue; + ovalue = 0; + pos = 0; + } + } + if ( pos != 0 ) + *ncp++ = ovalue; + return rv; +} + +static object * +imageop_grey2grey2(self, args) + object *self; + object *args; +{ + int x, y, len; + unsigned char *cp, *ncp; + unsigned char ovalue; + object *rv; + int i; + int pos; + + + if ( !getargs(args, "(s#ii)", &cp, &len, &x, &y) ) + return 0; + + if ( x*y != len ) { + err_setstr(ImageopError, "String has incorrect length"); + return 0; + } + + rv = newsizedstringobject(NULL, (len+3)/4); + if ( rv == 0 ) + return 0; + ncp = (unsigned char *)getstringvalue(rv); + pos = 0; + ovalue = 0; + for ( i=0; i < len; i++ ) { + ovalue |= (cp[i] & 0xc0) >> pos; + pos += 2; + if ( pos == 8 ) { + *ncp++ = ovalue; + ovalue = 0; + pos = 0; + } + } + if ( pos != 0 ) + *ncp++ = ovalue; + return rv; +} + +static object * imageop_dither2mono(self, args) object *self; object *args; @@ -213,6 +295,51 @@ imageop_dither2mono(self, args) } static object * +imageop_dither2grey2(self, args) + object *self; + object *args; +{ + int x, y, len; + unsigned char *cp, *ncp; + unsigned char ovalue; + object *rv; + int i; + int pos; + int sum, nvalue; + + + if ( !getargs(args, "(s#ii)", &cp, &len, &x, &y) ) + return 0; + + if ( x*y != len ) { + err_setstr(ImageopError, "String has incorrect length"); + return 0; + } + + rv = newsizedstringobject(NULL, (len+3)/4); + if ( rv == 0 ) + return 0; + ncp = (unsigned char *)getstringvalue(rv); + pos = 1; + ovalue = 0; + for ( i=0; i < len; i++ ) { + sum += cp[i]; + nvalue = sum & 0x180; + sum -= nvalue; + ovalue |= nvalue >> pos; + pos += 2; + if ( pos == 9 ) { + *ncp++ = ovalue; + ovalue = 0; + pos = 1; + } + } + if ( pos != 0 ) + *ncp++ = ovalue; + return rv; +} + +static object * imageop_mono2grey(self, args) object *self; object *args; @@ -252,6 +379,82 @@ imageop_mono2grey(self, args) return rv; } +static object * +imageop_grey22grey(self, args) + object *self; + object *args; +{ + int x, y, len, nlen; + unsigned char *cp, *ncp; + unsigned char ovalue; + object *rv; + int i, pos, value, nvalue; + + if ( !getargs(args, "(s#ii)", &cp, &len, &x, &y) ) + return 0; + + nlen = x*y; + if ( (nlen+3)/4 != len ) { + err_setstr(ImageopError, "String has incorrect length"); + return 0; + } + + rv = newsizedstringobject(NULL, nlen); + if ( rv == 0 ) + return 0; + ncp = (unsigned char *)getstringvalue(rv); + + pos = 0; + for ( i=0; i < nlen; i++ ) { + if ( pos == 0 ) { + value = *cp++; + pos = 8; + } + pos -= 2; + nvalue = (value >> pos) & 0x03; + *ncp++ = nvalue | (nvalue << 2) | (nvalue << 4) | (nvalue << 6); + } + return rv; +} + +static object * +imageop_grey42grey(self, args) + object *self; + object *args; +{ + int x, y, len, nlen; + unsigned char *cp, *ncp; + unsigned char ovalue; + object *rv; + int i, pos, value, nvalue; + + if ( !getargs(args, "(s#ii)", &cp, &len, &x, &y) ) + return 0; + + nlen = x*y; + if ( (nlen+1)/2 != len ) { + err_setstr(ImageopError, "String has incorrect length"); + return 0; + } + + rv = newsizedstringobject(NULL, nlen); + if ( rv == 0 ) + return 0; + ncp = (unsigned char *)getstringvalue(rv); + + pos = 0; + for ( i=0; i < nlen; i++ ) { + if ( pos == 0 ) { + value = *cp++; + pos = 8; + } + pos -= 4; + nvalue = (value >> pos) & 0x0f; + *ncp++ = nvalue | (nvalue << 4); + } + return rv; +} + /* static object * imageop_mul(self, args) @@ -291,8 +494,13 @@ static struct methodlist imageop_methods[] = { { "crop", imageop_crop }, { "scale", imageop_scale }, { "grey2mono", imageop_grey2mono }, + { "grey2grey2", imageop_grey2grey2 }, + { "grey2grey4", imageop_grey2grey4 }, { "dither2mono", imageop_dither2mono }, + { "dither2grey2", imageop_dither2grey2 }, { "mono2grey", imageop_mono2grey }, + { "grey22grey", imageop_grey22grey }, + { "grey42grey", imageop_grey42grey }, { 0, 0 } }; |