AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2002.01.16 11:07 "How to interpret 16-bit GrayScale image?", by Bad Badtz
2002.01.16 14:52 "RE: How to interpret 16-bit GrayScale image?", by Paul Beaty
2002.01.21 03:06 "RE: How to interpret 16-bit GrayScale image?", by Bad Badtz
2002.01.16 16:12 "Re: How to interpret 16-bit GrayScale image?", by Martí_Maria
2002.01.24 05:07 "Re: How to interpret 16-bit GrayScale image?", by Kevin D. Quitt
[...]

2002.01.16 14:52 "RE: How to interpret 16-bit GrayScale image?", by Paul Beaty

Nichole,

Unsigned 16-bit data means you have the possibility of a total value range of 65536 (0 - 65535) values. This does not mean they are all being used. Typically, when GIS and remote sensing data are stored as unsigned 16-bit, there is a good reason. This may indicate the values represent something other than a simple shade or color. How do you interpret the values.... first, what type of data do you have? DEM, vegetation index, satellite image, scanned photo, GIS thematic data?

If file size is an issue, use pack-bit compression to compress the non-used values. Note that pack-bit compression is a loss-less compression.

Good Luck,

Paul

> -----Original Message-----
> From: owner-tiff@olympiakos.com [mailto:owner-tiff@olympiakos.com]On
> Behalf Of Bad Badtz
> Sent: Wednesday, January 16, 2002 6:07 AM
> To: tiff@olympiakos.com
> Subject: How to interpret 16-bit GrayScale image?

I have a GeoTIFF image that looks like a grayscale image when viewed with Erdas Imagine. This image has 16 bits per sample and 1 sample per pixel. The photometric interpretation is 1, meaning that it is a grayscale image, and this image has no color table.

How do i interpret the pixel values then? Should I construct an index table with 65536 colors? Are there so many colors? Or can I change the image to RGB colored instead?

Urgent!! Please help!!! Thanks in advance!!

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