[R] about image and rgb
Martin Maechler
maechler at stat.math.ethz.ch
Mon Jul 8 15:24:10 CEST 2002
>>>>> "Olivier" == Olivier Martin <olivier.martin at inrialpes.fr> writes:
Olivier> I have a 16 bit image (TIFF) and i want to analyse
Olivier> the pixels distribution. So, i obtain a matrix
Olivier> which values are between 0 and 2^16 -1.
ok
Olivier> Now i would like to represnt this image with the
Olivier> fucntions rgb() and image().
`perfect'
Olivier> I am not sure , but i think that only 256 colors
Olivier> are available.
what makes you think so? It's not true.
There are (2^8)^3 (i.e 24-bit) colors in R, as you can see
quickly from looking at the result of rgb(), e.g.
Now the for viewing thing is devices, i.e. hardware and
device-driver software.
A few years ago, still many Sun Workstations came with graphics
cards that only permitted 8-bit (i.e. 256 different colors at a time).
Can you be more specific about your problems?
Olivier> So is there a solution to represent all the palette
Olivier> of the colors or i have to limit the
Olivier> representations with 256 colors.
Martin Maechler <maechler at stat.math.ethz.ch> http://stat.ethz.ch/~maechler/
Seminar fuer Statistik, ETH-Zentrum LEO C16 Leonhardstr. 27
ETH (Federal Inst. Technology) 8092 Zurich SWITZERLAND
phone: x-41-1-632-3408 fax: ...-1228 <><
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