pixmap-class             package:pixmap             R Documentation

_C_l_a_s_s _F_a_m_i_l_y "_p_i_x_m_a_p".

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

     The family '"pixmap"' (``pixel maps'') of classes provides methods
     for creating, plotting and converting bitmapped images in
     currently three different formats: RGB ('"pixmapRGB"'), grey
     ('"pixmapGrey"')and indexed pixmaps ('"pixmapIndexed"').

_O_b_j_e_c_t_s _f_r_o_m _t_h_e _C_l_a_s_s:

     Objects can be created by calls of the form 'new("pixmap", ...)'
     or using the creator functions 'pixmap' (similar for all child
     classes of name ('"pixmapXXX"').

_S_l_o_t_s:

     '_s_i_z_e': Object of class '"integer"' and length 2 (number of rows
          and columns).

     '_c_e_l_l_r_e_s': Object of class '"numeric"' and length 2 specifying the
          cell resolution of each pixel in user coordinates.

     '_b_b_o_x': Object of class '"numeric"' and length 4, the coordinates
          of the bounding box (x bottom, y bottom, x top, y top).

     '_c_h_a_n_n_e_l_s': A character vector naming the channel slots of the
          object ('NULL' for indexed pixmaps).

     '_r_e_d', '_g_r_e_e_n', '_b_l_u_e': Only for class '"pixmapRGB"' with matrices
          specifying the red, green and blue channel of the picture.

     '_g_r_e_y': Only for class '"pixmapGrey"', a matrix specifying the
          grey intensity (0=black, 1=white) of the picture.

     '_c_o_l': Only for class '"pixmapGrey"', a character vector with a
          map of color names.

     '_i_n_d_e_x': Only for class '"pixmapIndexed"', an integer matrix with
          codes from the color map.

_D_e_t_a_i_l_s:

     Class '"pixmap"' specifies the basic geometry of a picture: the
     size in pixels together with information for an optional
     coordinate system, see 'pixmap' for details.

     Grey and indexed pixmaps are besically matrices (contained in the
     'grey' or 'index' slot, respectively). The element '[1,1]'
     corresponds to the upper left corner as usual. For grey pixmaps
     the elements must be between 0 (black) and 1 (white). Indexed
     pixmaps have integer elements, each giving the index number
     corresponding to the palette specified in slot '"col"'. Colors are
     given using the usual R color strings (either names like '"red"'
     or hex values like '"#FF0000"'). Alternatively, a function to
     create a color palette can be specified, see 'rainbow' or
     'heat.colors' for examples.

     RGB pixmaps have three matrices for each of the three color
     channels. Elements of the matrices must be between 0 (=color off)
     and 1 (=color at maximum intensity).

     Methods for coercion between all formats are available.

     Class '"pixmapChannels"' is a helper parent class currently
     containing classes '"pixmapRGB"' and '"pixmapGrey"'.

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

     Friedrich Leisch

_S_e_e _A_l_s_o:

     'pixmap'

