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Add option for setting luminance & chrominance quality independently (currently only works if using libjpeg v7 or v8 code base)

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git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@248 632fc199-4ca6-4c93-a231-07263d6284db
This commit is contained in:
DRC
2010-10-10 07:21:55 +00:00
parent 2cdd2ae753 a4ecaacde6
commit 294079cbe0
4 changed files with 98 additions and 30 deletions
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55
rdswitch.c
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@@ -9,6 +9,7 @@
* command-line switches. Switches processed here are:
* -qtables file Read quantization tables from text file
* -scans file Read scan script from text file
* -quality N[,N,...] Set quality ratings
* -qslots N[,N,...] Set component quantization table selectors
* -sample HxV[,HxV,...] Set component sampling factors
*/
@@ -69,9 +70,12 @@ read_text_integer (FILE * file, long * result, int * termchar)
}
#if JPEG_LIB_VERSION < 70
static int q_scale_factor = 100;
#endif
GLOBAL(boolean)
read_quant_tables (j_compress_ptr cinfo, char * filename,
int scale_factor, boolean force_baseline)
read_quant_tables (j_compress_ptr cinfo, char * filename, boolean force_baseline)
/* Read a set of quantization tables from the specified file.
* The file is plain ASCII text: decimal numbers with whitespace between.
* Comments preceded by '#' may be included in the file.
@@ -108,7 +112,12 @@ read_quant_tables (j_compress_ptr cinfo, char * filename,
}
table[i] = (unsigned int) val;
}
jpeg_add_quant_table(cinfo, tblno, table, scale_factor, force_baseline);
#if JPEG_LIB_VERSION >= 70
jpeg_add_quant_table(cinfo, tblno, table, cinfo->q_scale_factor[tblno],
force_baseline);
#else
jpeg_add_quant_table(cinfo, tblno, table, q_scale_factor, force_baseline);
#endif
tblno++;
}
@@ -262,6 +271,46 @@ bogus:
#endif /* C_MULTISCAN_FILES_SUPPORTED */
GLOBAL(boolean)
set_quality_ratings (j_compress_ptr cinfo, char *arg, boolean force_baseline)
/* Process a quality-ratings parameter string, of the form
* N[,N,...]
* If there are more q-table slots than parameters, the last value is replicated.
*/
{
int val = 75; /* default value */
int tblno;
char ch;
for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
if (*arg) {
ch = ','; /* if not set by sscanf, will be ',' */
if (sscanf(arg, "%d%c", &val, &ch) < 1)
return FALSE;
if (ch != ',') /* syntax check */
return FALSE;
/* Convert user 0-100 rating to percentage scaling */
#if JPEG_LIB_VERSION >= 70
cinfo->q_scale_factor[tblno] = jpeg_quality_scaling(val);
#endif
while (*arg && *arg++ != ',') /* advance to next segment of arg string */
;
} else {
/* reached end of parameter, set remaining factors to last value */
#if JPEG_LIB_VERSION >= 70
cinfo->q_scale_factor[tblno] = jpeg_quality_scaling(val);
#endif
}
}
#if JPEG_LIB_VERSION >= 70
jpeg_default_qtables(cinfo, force_baseline);
#else
jpeg_set_quality(cinfo, val, force_baseline);
#endif
return TRUE;
}
GLOBAL(boolean)
set_quant_slots (j_compress_ptr cinfo, char *arg)
/* Process a quantization-table-selectors parameter string, of the form