AWARE [SYSTEMS] Imaging expertise for the Delphi developer
AWare Systems, Imaging expertise for the Delphi developer, Home TIFF and LibTiff Mailing List Archive

LibTiff Mailing List

TIFF and LibTiff Mailing List Archive
April 2006

Previous Thread
Next Thread

Previous by Thread
Next by Thread

Previous by Date
Next by Date

Contact

The TIFF Mailing List Homepage
This list is run by Frank Warmerdam
Archive maintained by AWare Systems



Valid HTML 4.01!



Thread

2006.04.07 07:34 "application supplied JPEGTables", by <yourpattern@126.com>
2006.04.07 09:01 "Re: application supplied JPEGTables", by Joris Van Damme
2006.04.07 10:05 "Re: application supplied JPEGTables", by <yourpattern@126.com>
2006.04.10 14:21 "Re: application supplied JPEGTables", by Gerben Vos
2006.04.11 06:45 "Re: application supplied JPEGTables", by <yourpattern@126.com>
2006.04.11 08:33 "Re: application supplied JPEGTables", by Joris Van Damme
2006.04.11 09:54 "Re: application supplied JPEGTables", by Gerben Vos
2006.04.11 10:12 "Re: application supplied JPEGTables", by Joris Van Damme

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.