Package com.luciad.imaging.operator

Class TLcdPixelRescaleOp

java.lang.Object

com.luciad.imaging.operator.ALcdImageOperator

com.luciad.imaging.operator.TLcdPixelRescaleOp

public final class TLcdPixelRescaleOp
extends ALcdImageOperator

Adjusts the pixel values of an image by applying a scale and offset.

This operation is equivalent to the following pseudo-code:

    pixelRescale(in_value) {
      normalized_in_value = normalize(in_value)
      normalized_out_value = normalized_in_value * scale + offset
      return denormalize(normalized_out_value)
    }
 

The normalization range is defined by the ALcdBandSemantics of the image. When rescaling a pixel with a "no data" value, the result is also "no data". You can find more details about the image processing model here.

Example

 // Using the static method:
 ALcdImage inputImage = ...;
 ALcdImage outputImage = TLcdPixelRescaleOp.pixelRescale(
     inputImage,
     new double[] { 1.0, 0.8, 0.2 },
     new double[] { 0.07, 0.05, 0.0 }
 );

 // Using a data object:
 ALcdImage inputImage = ...;
 TLcdPixelRescaleOp op = new TLcdPixelRescaleOp();
 ILcdDataObject params = op.getParameterDataType().newInstance();
 params.setValue(TLcdPixelRescaleOp.INPUT_IMAGE, inputImage);
 params.setValue(TLcdPixelRescaleOp.SCALES, new double[] { 1.0, 0.8, 0.2 });
 params.setValue(TLcdPixelRescaleOp.OFFSETS, new double[] { 0.07, 0.05, 0.0 });
 ALcdImage outputImage = op.apply(params);
 

Input

Output

Since:

2014.0

Nested Class Summary

Nested classes/interfaces inherited from class com.luciad.imaging.operator.ALcdImageOperator

ALcdImageOperator.ImageOperatorTypeBuilder

Field Summary

Fields

Modifier and Type	Field	Description
static final TLcdDataProperty	INPUT_IMAGE	The input image.
static final String	NAME	Name of the operator.
static final TLcdDataProperty	OFFSETS	The offset to apply to the scaled input image values.
static final TLcdDataType	PIXEL_RESCALE_FILTER_TYPE	Input data type of the operator.
static final TLcdDataProperty	SCALES	The scale to apply to the input image values.

Fields inherited from class com.luciad.imaging.operator.ALcdImageOperator

INPUT_IMAGE_NAME

Constructor Summary

Constructors

Constructor	Description
TLcdPixelRescaleOp()	Default constructor.

Method Summary

Modifier and Type	Method	Description
ALcdImage	apply(ILcdDataObject aParameters)	Applies this operator to the given input parameters.
static ALcdImage	pixelRescale(ALcdImage aSource, double[] aScales, double[] aOffsets)	Creates a pixel rescale operator for a given input image.

Methods inherited from class com.luciad.imaging.operator.ALcdImageOperator

createTypeBuilder, createTypeBuilder, equals, getParameterDataType, hashCode, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

NAME

public static final String NAME

Name of the operator.

See Also:

• Constant Field Values

INPUT_IMAGE

public static final TLcdDataProperty INPUT_IMAGE

The input image.

SCALES

public static final TLcdDataProperty SCALES

The scale to apply to the input image values.

OFFSETS

public static final TLcdDataProperty OFFSETS

The offset to apply to the scaled input image values.

Note that this scale applies to normalized input values. So for example to add 1 to each pixel of a color image with 8-bit unsigned integers you would use an offset of 1.0 / 255.0.

PIXEL_RESCALE_FILTER_TYPE

public static final TLcdDataType PIXEL_RESCALE_FILTER_TYPE

Input data type of the operator.

Constructor Details

TLcdPixelRescaleOp

public TLcdPixelRescaleOp()

Default constructor.

Method Details

apply

public ALcdImage apply(ILcdDataObject aParameters)

Description copied from class: ALcdImageOperator

Applies this operator to the given input parameters. The parameters are stored in a data object which must be of the type given by ALcdImageOperator.getParameterDataType().

Specified by:

apply in class ALcdImageOperator

Parameters:

aParameters - the parameters for the operator

Returns:

the image produced by the operator

pixelRescale

public static ALcdImage pixelRescale(ALcdImage aSource,
 double[] aScales,
 double[] aOffsets)

Creates a pixel rescale operator for a given input image. The operator takes arrays of scale factors and offsets as input, the length of which should be equal to the number of bands in the image.

Parameters:

aSource - the image to be processed

aScales - the scales to applied to each of the image's color bands

aOffsets - the offsets to be applied to each of the image's color bands

Returns:

the pixel rescale operator