LibTiff Mailing List
TIFF and LibTiff Mailing List Archive
March 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
Thread
2006.03.28 10:39 "JPEG in TIFF , how to directly write JPEG Tables in order to control the jpeg compr ession quality.", by <yourpattern@126.com>
Hi,All
I want to use my own JPEG quality tables. not the standard tables it generated.
how should i do .for example .i have 2 tables.:
static BYTE JPEG_QT_CHR[64] = {
12, 24, 24, 24, 27, 33, 39, 48,
24, 24, 26, 30, 34, 40, 47, 55,
24, 29, 34, 43, 52, 60, 69, 79,
39, 41, 47, 56, 69, 84, 100, 116,
57, 59, 65, 75, 90, 110, 134, 162,
83, 85, 91, 103, 120, 144, 177, 218,
119, 121, 129, 143, 164, 194, 236, 255,
172, 175, 185, 203, 230, 255, 255, 255 };
static BYTE JPEG_QT_LUM[64] = {
12, 17, 20, 33, 42, 53, 67, 86,
17, 20, 33, 37, 45, 56, 71, 90,
20, 33, 39, 46, 55, 67, 83, 103,
33, 37, 46, 59, 72, 86, 103, 125,
42, 45, 55, 72, 90, 110, 131, 157,
53, 56, 67, 86, 110, 137, 167, 202,
67, 71, 83, 103, 131, 167, 209, 255,
86, 90, 103, 125, 157, 202, 255, 255 };
how can i do to make the jpeg compress process use these 2 tables ?
Do TIFFSetField(ptif, JPEGTABLES,...) works ?