The number of map column values that are displayed along width and height can be specified using the [-mapwidth] and [-mapheight] options. These options control the number of map column values that are displayed in the horizontal and vertical directions of the display.
It is possible to specify the map pixel background color using the [-showcolormap] argument. When set to "TRUE", the pixel under the pointer will displayed as the background color for the label object in which the map values are displayed. When set to "FALSE", the background color is displayed as white.
When displaying map values, it is possible to show the displayed values or the actual map values using the [-displaypolicy] option. It is possible to display the values from the colormap being used to display the data (the RGB values that may have been converted/normalized for display) or to display the actual map segment from the data object being visualized (the map values before they are converted and/or normalized for use in defining the colors that appear on the screen).
By default, the Putmapval window will share its colormap with all other applications running at the same time; that is, it does not not use a "private colormap", but rather makes use of the "default colormap". It is possible to specify that the visualization display allocate its own private colormap or "grab" all available colors for its own use. This is done using the [-priv] option. When [-priv] is specified, moving the mouse pointer into the Putmapval window will cause the display to have its private colormap installed; moving the pointer out of the display window will cause the private colormap to be de-installed. This results in the "technoflashing" phenomenon characteristic of private colormap installation.
Color allocation can also be controlled and set to either "read-only" or "rea/write" using the [-alloc] argument. When set to "read-only", once a color cell has been allocated, it can have its color set only once; from then on, the color cell can be shared by multiple applications, but not changed. If the visualization display requires the color displayed to change, it must re-allocate the color cell, forcing a re-display of data. This can be an expensive procedure. In contrast, after a "read/write" color cell is allocated, it can have its color changed at any time without re-allocation; the data being displayed does not need to be redisplayed, and the color update process is much more efficient. However, the colors used in the visualization display cannot be shared by other applications.
The input file containing the map data to be displayed as three grids is monitored by default; the file is checked every 2 seconds for change, and if it has been modified, the map values are updated accordingly. The interval at which the input file is checked for modification may be specified using the [-update] argument. Setting the value to 0 turns checking off.
On creation, the window which displays the map values may be placed manually (the default method), or placed automatically. For automatic placement of the map values window, specify the desired location in device (screen) coordinates using the [-x] and [-y] arguments.
% putmapval -i image:mandril
% putmapval -i image:lizard