org.opengis.style

Interface RasterSymbolizer

All Superinterfaces:

Symbolizer

All Known Subinterfaces:

RasterSymbolizer

All Known Implementing Classes:

RasterSymbolizerImpl

@XmlElement(value="RasterSymbolizer")
public interface RasterSymbolizer
extends Symbolizer

The RasterSymbolizer describes how to render raster/matrix-coverage data (e.g., satellite photos, DEMs).

Since:

GeoAPI 2.2

Author:

Open Geospatial Consortium, Ian Turton, CCG, Johann Sorel (Geomatys)

Method Summary

Modifier and Type	Method and Description
Object	accept(StyleVisitor visitor, Object extraData) calls the visit method of a StyleVisitor
ChannelSelection	getChannelSelection() The ChannelSelection element specifies the false-color channel selection for a multi-spectral raster source (such as a multi-band satellite-imagery source).
ColorMap	getColorMap() The ColorMap element defines either the colors of a palette-type raster source or the mapping of fixed-numeric pixel values to colors.
ContrastEnhancement	getContrastEnhancement() The ContrastEnhancement element defines contrast enhancement for a channel of a false-color image or for a color image.
Symbolizer	getImageOutline() The ImageOutline element specifies that individual source rasters in a multi-raster set (such as a set of satellite-image scenes) should be outlined with either a LineStringSymbol or PolygonSymbol.
Expression	getOpacity() Indicates the level of translucency as a floating point number whose value is between 0.0 and 1.0 (inclusive).
OverlapBehavior	getOverlapBehavior() The OverlapBehavior element tells a system how to behave when multiple raster images in a layer overlap each other, for example with satellite-image scenes.
ShadedRelief	getShadedRelief() The ShadedRelief element selects the application of relief shading (or ?

Methods inherited from interface Symbolizer

getDescription, getGeometryPropertyName, getName, getUnitOfMeasure

Method Detail

getOpacity

@XmlElement(value="Opacity")
Expression getOpacity()

Indicates the level of translucency as a floating point number whose value is between 0.0 and 1.0 (inclusive). A value of zero means completely transparent. A value of 1.0 means completely opaque. If null, the default value is 1.0, totally opaque.

Returns:

expression

getChannelSelection

@XmlElement(value="ChannelSelection")
ChannelSelection getChannelSelection()

The ChannelSelection element specifies the false-color channel selection for a multi-spectral raster source (such as a multi-band satellite-imagery source). Either a channel may be selected to display in each of red, green, and blue, or a single channel may be selected to display in grayscale. (The spelling ?gray? is used since it seems to be more common on the Web than ?grey? by a ratio of about 3:1.) Contrast enhancement may be applied to each channel in isolation. Channels are identified by a system and data-dependent character identifier. Commonly, channels will be labelled as ?1?, ?2?, etc.

Returns:

the ChannelSelection object set or null if none is available.

getOverlapBehavior

@XmlElement(value="OverlapBehavior")
OverlapBehavior getOverlapBehavior()

The OverlapBehavior element tells a system how to behave when multiple raster images in a layer overlap each other, for example with satellite-image scenes. LATEST_ON_TOP and EARLIEST_ON_TOP refer to the time the scene was captured. AVERAGE means to average multiple scenes together. This can produce blurry results if the source images are not perfectly aligned in their geo-referencing. RANDOM means to select an image (or piece thereof) randomly and place it on top. This can produce crisper results than AVERAGE potentially more efficiently than LATEST_ON_TOP or EARLIEST_ON_TOP. The default behaviour is system-dependent.

Returns:

LATEST_ON_TOP,EARLIEST_ON_TOP, AVERAGE or RANDOM

getColorMap

@XmlElement(value="ColorMap")
ColorMap getColorMap()

The ColorMap element defines either the colors of a palette-type raster source or the mapping of fixed-numeric pixel values to colors. For example, a DEM raster giving elevations in meters above sea level can be translated to a colored image with a ColorMap. The quantity attributes of a color-map are used for translating between numeric matrixes and color rasters and the ColorMap entries should be in order of increasing numeric quantity so that intermediate numeric values can be matched to a color (or be interpolated between two colors). Labels may be used for legends or may be used in the future to match character values. Not all systems can support opacity in colormaps. The default opacity is 1.0 (fully opaque). Defaults for quantity and label are system-dependent.

Returns:

the ColorMap for the raster

getContrastEnhancement

@XmlElement(value="ContrastEnhancement")
ContrastEnhancement getContrastEnhancement()

The ContrastEnhancement element defines contrast enhancement for a channel of a false-color image or for a color image. In the case of a color image, the relative grayscale brightness of a pixel color is used. ?Normalize? means to stretch the contrast so that the dimmest color is stretched to black and the brightest color is stretched to white, with all colors in between stretched out linearly. ?Histogram? means to stretch the contrast based on a histogram of how many colors are at each brightness level on input, with the goal of producing equal number of pixels in the image at each brightness level on output. This has the effect of revealing many subtle ground features. A ?GammaValue? tells how much to brighten (value greater than 1.0) or dim (value less than 1.0) an image. The default GammaValue is 1.0 (no change). If none of Normalize, Histogram, or GammaValue are selected in a ContrastEnhancement, then no enhancement is performed.

Returns:

the ContrastEnhancement

getShadedRelief

@XmlElement(value="ShadedRelief")
ShadedRelief getShadedRelief()

The ShadedRelief element selects the application of relief shading (or ?hill shading?) to an image for a three-dimensional visual effect. It is defined as: Exact parameters of the shading are system-dependent (for now). If the BrightnessOnly flag is ?0? (false, default), the shading is applied to the layer being rendered as the current RasterSymbol. If BrightnessOnly is ?1? (true), the shading is applied to the brightness of the colors in the rendering canvas generated so far by other layers, with the effect of relief-shading these other layers. The default for BrightnessOnly is ?0? (false). The ReliefFactor gives the amount of exaggeration to use for the height of the ?hills.? A value of around 55 (times) gives reasonable results for Earth-based DEMs. The default value is system-dependent.

Returns:

the shadedrelief object

getImageOutline

@XmlElement(value="ImageOutline")
Symbolizer getImageOutline()

The ImageOutline element specifies that individual source rasters in a multi-raster set (such as a set of satellite-image scenes) should be outlined with either a LineStringSymbol or PolygonSymbol.

An Opacity of 0.0 can be selected for the main raster to avoid rendering the main-raster pixels, or an opacity can be used for a PolygonSymbolizer Fill to allow the main-raster data be visible through the fill.

Returns:

The relevent symbolizer

accept

@Extension
Object accept(StyleVisitor visitor,
                         Object extraData)

calls the visit method of a StyleVisitor

Specified by:

accept in interface Symbolizer

Parameters:

visitor - the style visitor

Returns:

value produced