AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2000.10.04 16:24 "PHOTOMETRIC_YCBCR", by Raj Kumar S.
[...]
2000.10.06 14:21 "RE: Old-style JPEG and HP 9100C Digital Sender", by Martin Bailey
2000.10.06 14:44 "RE: Old-style JPEG and HP 9100C Digital Sender", by Ed Grissom
2000.10.06 15:04 "RE: Old-style JPEG and HP 9100C Digital Sender", by Martin Bailey
[...]

2000.10.06 14:44 "RE: Old-style JPEG and HP 9100C Digital Sender", by Ed Grissom

In a previous message, Martin wrote:

> At 14:31 06/10/00, Grissom, Ed wrote:

Transparent Value (not a mask)

Yes to both

"No Data" value

??

It has been pointed out to me that these two (TransparencyValue/NODATAValue) are essentially the same. Graphics Arts folks want transparency whereas Remote Sensing types say "we did not collect data for this point in the grid". Also, when images are warped from one projection to another, it is very likely that there are edge pixels that do not map to anything in the original image and should be recorded as "NO DATA" for this position.

--
ed grissom

egrissom@ziimaging.com