TIFF and LibTiff Mail List Archive


2003.04.08 14:04 "please help with LZW", by Hailin Shen
2003.04.08 14:24 "RE: please help with LZW", by Carter John-jcarte01
2003.04.08 18:46 "RE: please help with LZW", by
2003.04.09 21:40 "Newbie Question (Offset value)", by Harring Figueiredo
2003.04.09 23:20 "trouble with LZW bit order", by Hailin Shen
2003.04.10 13:20 "Re: Newbie Question (Offset value)", by Greg Roberts
2003.04.10 14:28 "Re: Newbie Question (Offset value)", by Phillip Seaver
2003.04.11 21:34 "Re: Newbie Question (Offset value)", by Harring Figueiredo

2003.04.08 18:46 "RE: please help with LZW", by

If you apply tiffinfo on your image does it tell you 12bits/sample? If yes, I'm really interested to received your image. I can send you a LZW compressed images 16bits/sample in exchange! diana

-----Message d'origine-----
De: Hailin Shen []
Date: mardi 8 avril 2003 16:04
Objet: please help with LZW

Dear All,

I have a project in image analysis. The images I got are essentially multipage tiff format with private tags. Image data are compressed with LZW and preprocess by horizontal differencing. The bit per sample is 16. But I was told images are 512*512*12bit. 512*512 is the size of image.

I wonder what the LZW characters are for data after horizontal differencing for my case, since data could be positive or negative. At the position of stripoffsets, the hex number are '80 07 80 0F 17 F8 24 00 E8 7F 85 ....', ' 80 05 C0 27 A7 FB B9 FE 9E 00 1A ...' I could not figure out how to decode properly with clear code 256. File format is IEEE little-endian format. Any information is welcome!

The project is completely for academic study.

Thanks in advance for your kind help.