Display Tab

The Display tab (pictured below) specifies the color intensity (brightness/darkness), color transparency, blending, anti-aliasing, and texture mapping of the selected layers.

Access the display options from the control center using the Layer Options toolbar button, or right clicking on the layer name and selecting Options. It will also open when double-clicking on the layer name. The Raster Options and Elevation options dialogs contain a display tab.

Color Intensity

The Color Intensity setting controls whether displayed pixels are lightened or darkened before being displayed. It may be useful to lighten or darken raster overlays in order to see overlaying vector data clearly.

Translucency

The Translucency setting controls to what degree the overlay displays the overlays underneath it. Settings closer to Transparent make the overlay increasingly more see-through, allowing you to blend overlapping data.

Transparency

In the Transparency section, the Transparent option allows a particular color (or colors) to be displayed transparently, making it possible to see through a layer to the layers underneath.

The Set Transparent Color... button allows the user to select the color to treat as transparent.

With palette files, multiple colors may be selected using the CTRL or SHIFT key and selecting the palette colors. CTRL can also be used with the Pick from Map tool to pick multiple colors in a palette file.

 

Pick Color From Map - when this option is selected the cursor will change to an eyedropper. Click on any 2D map to select the color value at the cursor location.

Add to Custom Colors - This adds the color to the list of custom colors, shown below the basic colors.

The Exact to Fuzzy slider in the Transparency section controls how similar to the selected transparent color(s) that a color in the image has to be before it is also treated as transparent. The Exact side means that only exact matches on color will be treated as transparent, moving the slider towards the Fuzzy side makes progressively less similar colors be treated as transparent. This is useful for getting rid of colors in lossy formats like JPG and ECW where the colors are not exact.

For Example: When viewing a DRG on top of a DOQ, making the white in the DRG transparent makes it possible to see much of the DOQ underneath.

Online Layer Detail Offset

The Online Layer Detail Offset allows for online layers to draw data at a lower resolution for faster display. The detail control of online layers will enable pulling data from lower or higher resolution layers, rather than the default screen resolution calculation.

Blend Mode

The Blend Mode setting controls how an overlay is blended with underlying overlays, in addition to the Translucency setting. These settings allow Photoshop-style filters to be applied to overlays. The results from a particular blend mode with different sets of overlays can often be difficult to predict. It is best to experiment with different settings. The Hard Light setting works well with satellite imagery overlaid on DEMs, but the others can be quite useful as well.

Blend Mode Tip: The Apply Color setting is useful for applying color to a grayscale overlay, such

as using a low-resolution color LANDSAT image to colorize a high-resolution grayscale satellite image. The SPOT Natural Color blend mode combines the color channels in the topmost layer using the common algorithm for generating natural color imagery from images from the SPOT HRV multi-spectral sensor [Red = B2; Green = ( 3 * B1 + B3 ) / 4; Blue = ( 3 * B1 - B3 ) / 4]. The Pseudo Natural Color blend mode combines the color channels within a single image using a common algorithm for generating natural color imagery from CIR imagery. The Color to Grayscale blend mode converts a color image to grayscale.

Resampling

The Resampling option allows you to control how the color value for each displayed/export location is determined based on the values in the file. The following resampling methods are supported:

Texture Map

The Texture Map option allows a 2D raster overlay to be draped over loaded 3D elevation overlays. Selecting the check box causes the overlay to use any available data from underlying elevation layers to determine how to color the DRG or DOQ. The result is a shaded relief map.