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2006.04.11 06:45 "Re: application supplied JPEGTables", by <yourpattern@126.com>
Thanks ,all
Gerben,
Your idea is good, and what i do right now is as follows:
I define 2 Jpeg quantization tables.
and with the codes:
if(bCustomJpegTbls){
jpeg_add_quant_table(cinfo,0,JPEG_QT_CUSTOM_LUM,100,force_baseline);
jpeg_add_quant_table(cinfo,1,JPEG_QT_CUSTOM_CHR,100,force_baseline);
}
else{
/* Set up two quantization tables using the specified scaling */
jpeg_add_quant_table(cinfo, 0, std_luminance_quant_tbl,
scale_factor, force_baseline);
jpeg_add_quant_table(cinfo, 1, std_chrominance_quant_tbl,
scale_factor, force_baseline);
}
in jpeg_set_linear_quality function.
JPEG_QT_CUSTOM_LUM and JPEG_QT_CUSTOM_CHR are 2 global tables i used for
specified custom quantization tables.