displayDataset             package:rgdal             R Documentation

_D_i_s_p_l_a_y _a _G_D_A_L _d_a_t_a_s_e_t

_D_e_s_c_r_i_p_t_i_o_n:

     Display a GDAL dataset allowing for subscenes and decimation,
     allowing very large images to be browsed

_U_s_a_g_e:

     displayDataset(x, offset=c(0, 0), region.dim=dim(x), reduction = 1, band = 1, col = NULL, reset.par = TRUE, max.dim = 500, ...)

_A_r_g_u_m_e_n_t_s:

       x: a three-band GDALReadOnlyDataset object

  offset: Number of rows and columns from the origin (usually the upper
          left corner) to begin reading from; presently ordered (y,x) -
          this may change

region.dim: The number of rows and columns to read from the dataset;
          presently ordered (y,x) - this may change

reduction: a vector of length 1 or 2 recycled to 2 for decimating the
          input data, 1 retains full resultion, higher values decimate

    band: The band number (1-based) to read from

     col: default NULL, attempt to use band colour table and default to
          grey scale if not available

reset.par: default TRUE - reset par() settings on completion

 max.dim: default 500, forcing the image to a maximum dimension of the
          value

     ...: arguments passed to image.default()

_V_a_l_u_e:

     a list of the image data, the colour table, and the par() values
     on entry.

_A_u_t_h_o_r(_s):

     Tim Keitt

_R_e_f_e_r_e_n_c_e_s:

     <URL: http://www.gdal.org/>

_E_x_a_m_p_l_e_s:

     logo <- system.file("pictures/Rlogo.jpg", package="rgdal")[1]
     x <- GDAL.open(logo)
     opar <- par(no.readonly=TRUE)
     par(mfrow=c(2,2))
     displayDataset(x, band=1, reset.par=FALSE)
     displayDataset(x, band=2, reset.par=FALSE)
     displayDataset(x, band=3, reset.par=TRUE)
     par(opar)
     dx <- RGB2PCT(x, band=1:3)
     displayDataset(dx)
     GDAL.close(x)
     GDAL.close(dx)

