Colour-shaded Grid Image

Use the Colour-shaded Grid Image dialog (GRIDIMGS GX) to place a colour-shaded grid image on a map.

Colour-shaded Grid Image dialog options

Grid name

Select grid name

Script Parameter: GRIDIMGS.GRID

Shading effect

Select the shading effect option:

Normal (RGB) - shading using RGB model
Wet-look (HSV) – shading using Hue, Saturation, Value

If shading using "Wet-look (HSV)", the colour table specified is ignored. Instead, the hsvc.tbl and hsvg.tbl tables are used for the colour and shaded components of the image respectively.

Colour method

Specify the colour zoning method for rendering colour distributions. Select one of the options below:

  • As last displayed: the grid is displayed in its last viewed state: its previous colour transform is used, and the currently selected colour scheme will be ignored.

  • Default: the default colour distribution method is used.

  • Histogram equalization: your data values are evaluated, and the zones are statistically determined, such that data is equally divided among the histogram bins.
  • Normal distribution: your data is assumed to be normally distributed, and the zones are determined based on the standard distribution for a standard bell curve.
  • Linear: the range of data values are divided linearly into even increments.
  • Log-Linear: the zone values are updated based on the log distribution of the data, and the data is displayed using the log-linear colour distribution.

Script Parameter: GRIDIMGS.ZONE

Colour table

Select the colour scheme for rendering the colour-shaded grid image. If you mouse over the colour scheme entry, a tooltip will display the name of the colour table in its folder. To modify the selection, click on the colour entry and then navigate through the scheme categories.

Script Parameter: GRIDIMGS.COLOR

Brightness

The normal brightness is defined at 0. You can change the brightness from -100 (black) to 100 (white) using either the slider bar or by entering an exact value

Script Parameter: GRIDIMGS.BRIGHTNESS [range: 0 to 100]

Contour interval

The contour interval.

Script Parameter: GRIDIMGS.CONTOUR

Illumination inclination

Illumination inclination (Default 45 degrees).

Script Parameters: GRIDIMGS.INC

Illumination declination

Illumination declination (Default 45 degrees).

Script Parameters: GRIDIMGS.DEC

Vertical scale factor

Vertical scale factor.

Script Parameters: GRIDIMGS.SCL

Application Notes

Click the New Map button to display a grid on a new map. Click the Current Map button to display the grid on the current map.(For script file, set Script Parameter: GRIDIMGS.NEW to 1 to create a new map; 0 to use current map)

If a new map is specified, the range of the grid is used to create a basic map layout.

For the "Normal (RGB)" shading effect, the specified colour table and contour interval are used to display the original grid data and the grey.tbl table is used to display the shaded-relief grid.

If the "Wet-look (HSV)" effect is selected, the hsvg.tbl and hsvg.tbl are used to display the colour and shaded-relief grids respectively.

Oasis montaj will create a shaded-relief grid file with the same name as the input grid plus a suffix "_s". For example, if "mag.grd" is the grid name, Oasis montaj will create a shaded relief grid named "mag_s.grd".

You can use the Image Colour Tool to modify the shading parameters if desired.

If you want to see the same data shaded from different directions on different images, use "Grid/Filters/Shaded relief" (gridshad GX) to create separate shaded grids for each of the independent maps. The "2-grid composite" grid display can then be used to display the different shaded grids with the desired original data. Each image will then be controlled independently.