[R-sig-Geo] Plot (image( )) Real RGB Colors of an Imported GeoTIFF (readGDAL( ))

[Robert J. Hijmans]

Rodrigo, you can try plotRGB in raster. Robert

On Tue, Jun 22, 2010 at 6:57 AM, Rodrigo Aluizio <r.aluizio at gmail.com> wrote:
> Hi List members.
>
> I’m actually able to import a Georeferenced image (.tiff) using readGDAL
> {rgdal} and plot it using image {Graphics}.
>
> But the colors options available in the image function (topo.colors,
> heat.colors, terrain.colors, etc) aren’t able to adequately reproduce the
> original image. The tiff file represent land and ocean, so I need brow and
> green tones to land and blue tones to ocean. I was able to create the blue
> tones with colorRampPalette () but these blue tones are also applied to the
> land.
>
> Once imported the object containing the raster georeferenced file brings
> three data columns with bands (RGB maybe) values of each cell (I guess).
> Isn’t there a way to reproduce the real colors using these columns
> information or any other way to do so?
>
>
>
> Thank you on advance for the patience and help.
>
>
>
> Below, some useful information on the object:
>
>
>
>>
> BC<-readGDAL('C:/Users/Rodrigo/Documents/Shapefiles/Campos/BaciaCampos-GE-SA
> D69-LongLat.tiff')
>
> C:/Users/Rodrigo/Documents/Shapefiles/Campos/BaciaCampos-GE-SAD69-LongLat.ti
> ff has GDAL driver GTiff
>
> and has 3350 rows and 3015 columns
>
>
>
>> summary(BC)
>
> Object of class SpatialGridDataFrame
>
> Coordinates:
>
>        min       max
>
> x -42.15808 -39.58503
>
> y -23.74079 -21.08709
>
> Is projected: FALSE
>
> proj4string : [+proj=longlat +ellps=aust_SA +no_defs]
>
> Number of points: 2
>
> Grid attributes:
>
>  cellcentre.offset     cellsize cells.dim
>
> x         -42.15765 0.0008534147      3015
>
> y         -23.74040 0.0007921499      3350
>
> Data attributes:
>
>     band1            band2            band3
>
>  Min.   :  0.00   Min.   :  0.00   Min.   :  0.0
>
>  1st Qu.: 48.00   1st Qu.: 67.00   1st Qu.: 95.0
>
>  Median : 70.00   Median : 89.00   Median :117.0
>
>  Mean   : 65.17   Mean   : 83.37   Mean   :117.7
>
>  3rd Qu.: 76.00   3rd Qu.: 97.00   3rd Qu.:150.0
>
>  Max.   :255.00   Max.   :255.00   Max.   :255.0
>
>
>
> Regards
>
>
>
> -------------------------------------------------------------
>
> MSc.  <mailto:r.aluizio at gmail.com> Rodrigo Aluizio
>
> Centro de Estudos do Mar/UFPR
> Laboratório de Micropaleontologia
> Avenida Beira Mar s/n - CEP 83255-000
> Pontal do Paraná - PR - Brasil
>
>
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