AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2005.03.22 17:20 "[Tiff] tif_jpeg.c and 12bit JPEG Files", by Frank Warmerdam
2005.03.22 18:03 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Lee Howard
2005.03.22 18:17 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Frank Warmerdam
2005.03.22 18:33 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Joris Van Damme
2005.03.22 18:04 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Bob Friesenhahn
2005.03.22 18:10 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Frank Warmerdam
2005.03.22 18:22 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Bob Friesenhahn
2005.03.22 20:00 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by David Gilbert
2005.03.22 20:25 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Bob Friesenhahn
2005.03.22 20:38 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Frank Warmerdam
2005.03.22 21:59 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Bob Friesenhahn
2005.03.22 22:28 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Frank Warmerdam
2005.03.22 22:41 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Bob Friesenhahn
2005.03.29 11:24 "Re[2]: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Jean-Yves Le Ridant
2005.03.29 16:08 "Re[2]: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Bob Friesenhahn
2005.04.01 08:08 "Re[3]: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Jean-Yves Le Ridant
2005.03.22 21:19 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Chris Cox
2005.03.22 21:36 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Bob Friesenhahn
2005.03.31 10:04 "Re[2]: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Jean-Yves Le Ridant
2005.03.22 21:37 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Chris Losinger
2005.03.23 14:08 "RE: [Tiff] tif_jpeg.c and 12bit JPEG Files", by Jeff Mather

2005.03.22 20:00 "Re: [Tiff] tif_jpeg.c and 12bit JPEG Files", by David Gilbert

The only way that makes sense is for 12 bit samples to be returned the same as for an uncompressed 12 bit TIFF file. Likewise, 12 bit samples should be consumed so that the only thing special the library user needs to do is request JPEG compression, and possibly JPEG RGB mode.

Well... the "issue" is that the jpeg library treats 12 bit samples as 12 bit stored in 16 bit integers. JPEG's transformation uses 16 bit ints for the math anyways... so someone has to do the upsampling. Both the classic and the MK1 jpeg expect the user to do this.


Editor's note: This mail was not originally archived, and has been reconstructed from quotes.