oracle.spatial.georaster.image

Class GeoRasterImageProcessUtil

java.lang.Object

oracle.spatial.georaster.image.GeoRasterImageProcessUtil

public class GeoRasterImageProcessUtil
extends java.lang.Object

The GeoRasterImageProcessUtil class provides the following basic image processing functions:

     normalize
     equalize
     scale
     piecewiseLinearStretch
     changeContrast
     changeBrightness
     changeThreshold
 

The GeoRasterImageProcessUtil object is initiated by a RenderedImage object as follows:

     GeoRasterImageProcessUtil util=new GeoRasterImageProcessUtil(image);
 

When creating a GeoRasterImageProcessUtil object, it is the application's responsibility to ensure that the current working image is not null.

Constructor Summary

Constructors

Constructor and Description
GeoRasterImageProcessUtil(java.awt.image.RenderedImage img) Constructs an GeoRasterProcessUtil object using the given RenderedImage object.

Method Summary

Modifier and Type	Method and Description
java.awt.image.RenderedImage	amplitudeRescaling() Performs amplitude rescaling; the method will calculate extreme values for the image at first, and then scale extreme low and extreme high values to 0 and 256 respectively.
java.awt.image.RenderedImage	amplitudeRescaling(double low, double high) Performs amplitude rescaling; low value and high value will be scaled to 0 and 256, respectively.
java.awt.image.RenderedImage	changeBrightness(int b) change brightness of the current working image
java.awt.image.RenderedImage	changeContrast(double contrast) Changes the contrast of the current working image.
java.awt.image.RenderedImage	changeThreshold(double low_p, double high_p, double target) Applies a threshold operation on the current working image; maps all the pixels of this image whose value falls within a specified range to a specified constant.
java.awt.image.RenderedImage	equalize() Applies an equalization operation on the current working image.
java.awt.image.RenderedImage	getImage() Gets the current working image.
java.awt.image.RenderedImage	normalize() Applies a normalization operation on the current working image.
java.awt.image.RenderedImage	piecewiseLinearStretch() Applies a piecewise linear stretch operation on the current working image.
void	setImage(java.awt.image.RenderedImage img) Sets the current working image.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

GeoRasterImageProcessUtil

public GeoRasterImageProcessUtil(java.awt.image.RenderedImage img)

Constructs an GeoRasterProcessUtil object using the given RenderedImage object.

Parameters:

img - a RenderedImage object

Method Detail

setImage

public void setImage(java.awt.image.RenderedImage img)

Sets the current working image.

Parameters:

img - current working RenderedImage

getImage

public java.awt.image.RenderedImage getImage()

Gets the current working image.

Returns:

current working renderedImage.

amplitudeRescaling

public java.awt.image.RenderedImage amplitudeRescaling(double low,
                                                       double high)

Performs amplitude rescaling; low value and high value will be scaled to 0 and 256, respectively.

Parameters:

low - low value, which will be scaled to 0

high - high value, which will be scaled to 256

Returns:

a new RenderedImage object if scaling was successfully applied to the current working image, or null if the operation failed. Note: in both cases, the current working image is kept intact.

amplitudeRescaling

public java.awt.image.RenderedImage amplitudeRescaling()

Performs amplitude rescaling; the method will calculate extreme values for the image at first, and then scale extreme low and extreme high values to 0 and 256 respectively.

Returns:

a new RenderedImage object, if scaling was successfully applied to the current working image, or null if the operation failed. Note: in both cases, the current working image is kept intact.

normalize

public java.awt.image.RenderedImage normalize()

Applies a normalization operation on the current working image.

Returns:

a new RenderedImage object if the operation succeeded, or null if it failed. Note: in both cases, the current working image is kept intact.

piecewiseLinearStretch

public java.awt.image.RenderedImage piecewiseLinearStretch()

Applies a piecewise linear stretch operation on the current working image.

Returns:

a new RenderedImage object if the operation succeeded, or null if it failed. Note: in both cases, the current working image is kept intact.

equalize

public java.awt.image.RenderedImage equalize()

Applies an equalization operation on the current working image.

Returns:

a new RenderedImage object if the operation succeeded, or null if it failed. Note: in both cases, the current working image is kept intact.

changeBrightness

public java.awt.image.RenderedImage changeBrightness(int b)

change brightness of the current working image

Parameters:

b - brightness, data range is 0-256

Returns:

a new RenderedImage object if the operation succeeded, or null if it failed. Note: in both cases, the current working image is kept intact.

changeThreshold

public java.awt.image.RenderedImage changeThreshold(double low_p,
                                                    double high_p,
                                                    double target)

Applies a threshold operation on the current working image; maps all the pixels of this image whose value falls within a specified range to a specified constant. The range is specified by a low_p value and a high_p value, and the constant value is specified by the target parameter.

Parameters:

low_p - low end of data range

high_p - high end of data range

target - constant value for specific range of values

Returns:

a new RenderedImage object if the operation succeeded, or null if it failed. Note: in both cases, the current working image is kept intact.

changeContrast

public java.awt.image.RenderedImage changeContrast(double contrast)

Changes the contrast of the current working image.

Parameters:

contrast - contrast, data range is 0-256

Returns:

a new RenderedImage object if the operation succeeded, or null if it failed. Note: in both cases, the current working image is kept intact.