Display options

Raster map domain Image

 

Specify display options for a raster map with a domain Image.

Before a map is displayed in a map window, you have to answer some questions on how this layer should be displayed in the map window. Also, once a map is displayed in a map window, you may want to change the display options of a certain layer:

Dialog box options:

Info:

Select this check box if you want to see the pixel values when you press the left mouse button in a map window.

Clear this check box if you do not want to see pixel values.

Scale limits:

Select this check box when this map should be displayed or hidden depending on the scale specified in the scale control of the map window; specify the scale range within which the map should be displayed. The map will be automatically hidden if the scale of the map window is outside this range.

With this option you can achieve for instance, that very detailed maps (e.g. on cadastral units) are only displayed when using a large scale in a map window, or that very general maps which depict overviews are only displayed when using a small scales in a map window, etc.

Clear this check box when you wish to display the map regardless of the scale of the map window.

Transparent:

Select this check box when you wish to display this raster layer with a certain transparency. Any layer that has been added to the map window before, e.g. an image or a shadow map, will remain partly visible through the transparent raster layer. Subsequently, type a value for the transparency rate (percentage): value 1 means almost not transparent, and value 99 means almost totally transparent.

Clear this check box to just display the layer, i.e. non-transparent.

Mind:

  • For Transparency, the Display Settings of your screen must be set to 32 bit (True Color).
  • When the map window already displays another raster map, you can only add raster maps which have the same georeference. You can use the Resample operation to transform a raster map to a desired georeference.

Text:

Select this check box if you want to see pixel values displayed as text on top of the pixels. Subsequently, select a color for the text from the appearing Text Color list box. Clear this check box if you just want to see the image.

Representation:

Select a representation with which the map should be displayed; open the list box by clicking it. You can select one of the system representations, a user-defined representation value linked to domain Image, or a user-defined representation gradual. Or create a new representation value by clicking the little create button. By creating a representation value with the Representation Value/Gradual editor, you can make the image appear as if it was sliced but the original values are retained.

Stretch:

Stretching an image results in a better contrast.

  • In case the default system representation Gray was accepted:
  • Select the Stretch check box if you want to display the image with stretching. Subsequently, specify the stretch range. By default, the 1% interval values are given. This means that 1% of the first values in the histogram and 1% of the last values in the histogram are ignored during stretching.

    Clear this check box if you want to display the image without stretching.

  • In case a representation gradual was selected:
  • The map is always stretched and the user has to specify the stretch range. By default the 1% interval values are given.

  • In case a representation value was selected:
  • The image is displayed in the colors as defined in the representation value.

Light, etc:

Select option Light to display this map a little lighter than normal, select option Normal to display this map with normal brightness, or select option Dark to display this map a little darker than normal. Select option Gray to display this map in gray tones regardless of the selected representation.

Create Pyramid Layers:

 

In case pyramid layers are not yet available for this raster map:

  • Select this check box to create pyramid layers for this raster map. Pyramid layers speed up the display of large raster maps in a map window.
  • Clear this check box if you do not wish to create pyramid layers for this raster map.

For more information on pyramid layers, see ILWIS objects : Raster maps - Pyramid layers.

The first text line in this dialog box states the map type and the map name. Furthermore, the dialog box shows the description and domain of the map.

See also: