De: Uwe Ligges <ligges at statistik.tu-dortmund.de>
Asunto: Re: [R] Reading a TIFF file
A: "Julio Rojas" <jcredberry at ymail.com>
Cc: r-help at r-project.org
Fecha: viernes, 22 de abril de 2011, 12:37 pm
Unless you can provide a small
reproducible example (say a very small
tiff including the values you got from the non-R software)
it will be
hard to tell what is going on.
Uwe Ligges
On 22.04.2011 11:23, Julio Rojas wrote:
Dear all, I have been trying to speed up a process we
have been done in ArcGIS. We have to read a single layer
TIFF (monochrome image) in . For this, I have used the
"rtiff" package. After reading the TIFF file, I compared the
raw values for each pixel that I have in ArcGIS to the ones
obtained in R. In ArcGIS I have discrete values in the range
0..255, while in R I have continuous values between 0..1.
This, in itself might not be a problem if the values
obtained in R, times 255 would show the values obtained in
ArcGIS, but this is not the case. The images are very
different. I tried to settle matters using Photoshop, and
the values there are completely different from the other two
(using RGB, the K value (in CMYK) or the B value (in
HSB))!!!
Can somebody help me with this problem? Can I trust
"rtiff"? Should I stick to a very slow process in ArcGIS?
Why PS, which should be the perfect measuring stick, is
showing another set of values?
Thanks in advance. Regards.
Julio