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

  • Field Details

    • NAME

      public static final String NAME
      Name of the operator.
      See Also:

    • 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