Raster Style

Raster Style is applicable for raster format.

Image Adjustments

Opacity
Select the opacity using up and down buttons. You can choose any value between 0 and 100 where 0 is totally transparent and 100 is fully opaque. The default value is 100.
Contrast
Select the contrast using up and down buttons. You can choose any value between 0 and 100 where 0 is no contrast and 100 is fully contrast. Contrast helps in making a map more readable and clearer. Adjusting the contrast makes it easier to differentiate between raster image and additional layers that rest on top of the raster. The default value is 50.
Brightness
Select the brightness using up and down buttons. You can choose any value between 0 and 100 where 0 is no brightness and 100 is fully bright. Brightness helps in making a map more readable and clearer. Adjusting the brightness makes it easier to differentiate between raster image and additional layers that rest on top of the raster. The default value is 50.
Select the color to show as transparent
Select to specify the color that you want to become as transparent. A color picker with color palette appears once you have selected this check box. Select a color from the palette by clicking inside the palette. To change the color range, drag the color slider located below the color palette. The palette displays the colors falling in the selected range.
You can also provide a hex value, RGB, or HSL values to get the exact color you need. By default you see the Hex field but you can switch to RGB and HSL modes by successively clicking the small arrow button located in the right.
Note: You can reset the selected color by clicking Refresh and then you can start over the color selection.
Show as grayscale
Select to change the color raster image to grayscale. Shades range from white to black.
Override render style
Select if you wish to override the existing style applied on the layer with the new settings.

Display Mode

Note: The following settings are applicable when a table with MRR (Multi Resolution Raster) content is used to create the named layer.

The Display Mode allows you to map different bands in your raster dataset against red, green, and blue color channels to illuminate the image and derive useful insight. The different band combinations highlight different features in your raster data.

Select the display mode you want to apply on the raster. The supported modes are Pseudo, RGB, and Classified.
Note: Depending on the field type present in the input raster, the display mode options come enabled or disabled. Following rules apply:
Fields Enabled Display Mode
Classified or Image Palette Classified
Imagery or Continuous RGB
Imagery or Continuous Pseudo
Pseudo: The Pseudo display mode has the following settings:
Field, band
The field displays a combination of field followed by the band. If the input file has multiple fields and bands, select the required field, band from the drop-down list.
Raster quality
It has the following methods:
  • None: No resampling method is applied to the raster.
  • Nearest Neighbor: It calculates the value of each cell by performing a nearest neighbor assignment. This is the most basic technique that requires the least processing time of all the interpolation algorithms. This technique selects the nearest pixels to replace the original pixels when images are zoomed.
  • Bilinear: It considers the closest 2x2 neighborhood and calculates the new value of a cell based on a weighted distance average of the four nearest input cell. It provides smoother looking images than nearest neighbor. You can use this method for continuous data.
  • Cubic Spline (Local): It considers the closest 4x4 neighborhood and calculates the new value of a cell based on fitting a smooth curve through the 16 closest input cells. It requires more processing time. You can use this method for continuous data.
  • Cubic Spline (Global): It considers the closest 4x4 neighborhood and calculates the new value of a cell based on fitting a smooth curve through the 16 closest input cells. It requires more processing time. You can use this method for continuous data.
Advanced
Click Advanced to open the advanced settings for the Pseudo display mode.
Show hillshade
Select this option to display the hillshade effect on the raster. The hillshade allows you to obtain hypothetical illumination of a surface by determining the illumination values for each cell in a raster grid file. Hill shading darkens areas that are sloped or darkens areas that are obscured by higher elevated areas. This tool works on the premise of brightening areas that face the sun directly. Hill shading can significantly enhance the visualization of a surface for analysis or graphical display, especially when using transparency.
Show highlights
The Show highlights check box is enabled only when Show hillshade is selected. Select this option to control the way bright areas on the map are displayed.
Transformation type
You can select one from the following transformation types:
  • Linear: In this stretch method, all cell values of the raster are rescaled to new values in the output raster. For example, in any single-band, greyscale raster, the possible cell values range from 0-255. In practice, however, not all of these values will appear in the input raster. In input raster, the cell values range from 70-180, the linear stretching method will bring the minimum input value of 70 to the output value 0, and bring the maximum input value of 180 to output value 255. All intermediate values will change accordingly. When the image is displayed, it will have better contrast.
  • Logarithmic: In this method, the smaller cell values in the raster will be mapped to a wider range of colors. The larger values will be mapped to similar colors. The intermediate values are mapped to a shorter range of colors. The formula for calculating logarithmic stretch depends on the minimum and maximum values specified in the stretch range. Any values in the input raster that are smaller than the specified minimum stretch range value will obtain the same color as the minimum stretch range value. Similarly, any values in the input raster that are larger than the specified maximum stretch range value will obtain the same color as the maximum stretch range value.
  • Histogram Equalization: In this method, the values of an raster are converted into a number of output intervals. In doing so, all output intervals will contain an equal amount of cells. In other words, Histogram Equalization equalizes the intensity distribution of an image.
  • Custom Breaks: The user-defined breaks enable to apply custom coloring to the input raster through a variety of techniques. As the method changes and the clips/breaks are altered, the color distribution will be altered automatically. It can be used only with LUTColor render style.
Color Palette
Select a color palette to apply on the layer. Click and select a palette from the color picker and click OK. You will need to refresh the preview to see the updated color palette in effect.
RGB: The RGB display mode has the following settings:
Red channel
It represents the red mapping channel. It contains all field and band names of the input dataset. You can select a combination of field and band from the list to map the bands to the red channels. The field and band are separated by a hyphen.
Green channel
It represents the green mapping channel. It contains all field and band names of the input dataset. You can select a combination of field and band from the list to map the bands to the green channels. The field and band are separated by a hyphen.
Blue channel
It represents the blue mapping channel. It contains all field and band names of the input dataset. You can select a combination of field and band from the list to map the bands to the blue channels. The field and band are separated by a hyphen.
Raster quality
Select a raster quality from the drop down. Refer to Raster quality for more details.
Disable alpha channel
Select to disable the alpha channel. An alpha channel supports images with Alpha Channel transparency. Alpha channels are masks through which you can display images.
Advanced
Click Advanced to open the advanced settings for the RGB display mode.
Color transformation
There can be two ways in which the color transformation can be achieved:
  • All: Select this option to apply the same field, band combination to all the channels.
  • Individually: Select this option to apply different field, band combination to channels individually.
Transformation type
You can select one from the following transformation types:
  • Linear: In this stretch method, all cell values of the raster are rescaled to new values in the output raster. For example, in any single-band, greyscale raster, the possible cell values range from 0-255. In practice, however, not all of these values will appear in the input raster. In input raster, the cell values range from 70-180, the linear stretching method will bring the minimum input value of 70 to the output value 0, and bring the maximum input value of 180 to output value 255. All intermediate values will change accordingly. When the image is displayed, it will have better contrast.
  • Logarithmic: In this method, the smaller cell values in the raster will be mapped to a wider range of colors. The larger values will be mapped to similar colors. The intermediate values are mapped to a shorter range of colors. The formula for calculating logarithmic stretch depends on the minimum and maximum values specified in the stretch range. Any values in the input raster that are smaller than the specified minimum stretch range value will obtain the same color as the minimum stretch range value. Similarly, any values in the input raster that are larger than the specified maximum stretch range value will obtain the same color as the maximum stretch range value.
  • Histogram Equalization: In this method, the values of an raster are converted into a number of output intervals. In doing so, all output intervals will contain an equal amount of cells. In other words, Histogram Equalization equalizes the intensity distribution of an image.
  • Direct Mapping: The user-defined breaks enable to apply custom coloring to the input raster through a variety of techniques. As the method changes and the clips/breaks are altered, the color distribution will be altered automatically. It can be used only with LUTColor render style.
Classified: This mode is for Classified or ImagePalette type MRR data. The classified display mode has the following settings:
Field, Band
The field displays a combination of field followed by the band. Refer to Field, band for more details.
Disable alpha channel
Select to disable alpha channel. Refer to Disable alpha channel for more details.