Application: gvSIG desktop » gvSIG tools: ToolBox

package es.unex.sextante.gridCalculus.kernelFilter;

import es.unex.sextante.core.GeoAlgorithm;

import es.unex.sextante.core.Sextante;

import es.unex.sextante.dataObjects.IRasterLayer;

import es.unex.sextante.exceptions.GeoAlgorithmExecutionException;

import es.unex.sextante.exceptions.RepeatedParameterNameException;

import es.unex.sextante.parameters.FixedTableModel;

public class KernelFilterAlgorithm

         extends

            GeoAlgorithm {

   public static final String RESULT = "RESULT";

   public static final String KERNEL = "KERNEL";

   public static final String LAYER  = "LAYER";

   private IRasterLayer       m_Window;

   protected double           m_dValues[];

   private double             m_dNoData;

   private double             m_dCoeffs[];

   @Override

   public void defineCharacteristics() {

      final String sColumnNames[] = { "1", "2", "3" };

      setUserCanDefineAnalysisExtent(false);

      setName(Sextante.getText("User-defined_3_X_3_filter"));

      setGroup(Sextante.getText("Basic_tools_for_raster_layers"));

      try {

         m_Parameters.addInputRasterLayer(LAYER, Sextante.getText("Layer"), true);

         m_Parameters.addFixedTable(KERNEL, Sextante.getText("Filter_kernel"), sColumnNames, 3, true);

         addOutputRasterLayer(RESULT, this.getName());

      }

      catch (final RepeatedParameterNameException e) {

         Sextante.addErrorToLog(e);

      }

   }

   @Override

   public boolean processAlgorithm() throws GeoAlgorithmExecutionException {

      int x, y;

      int iNX, iNY;

      m_Window = m_Parameters.getParameterValueAsRasterLayer(LAYER);

      final FixedTableModel kernel = (FixedTableModel) m_Parameters.getParameterValueAsObject(KERNEL);

      m_Window.setFullExtent();

      final IRasterLayer result = getNewRasterLayer(RESULT, this.getName(), IRasterLayer.RASTER_DATA_TYPE_DOUBLE,

               m_Window.getLayerGridExtent());

      iNX = m_Window.getNX();

      iNY = m_Window.getNY();

      m_dValues = new double[9];

      m_dCoeffs = new double[9];

      m_dNoData = m_Window.getNoDataValue();

      result.setNoDataValue(m_dNoData);

      int i, j;

      int iCell = 0;

      for (i = 0; i < 3; i++) {

         for (j = 0; j < 3; j++) {

            try {

               m_dCoeffs[iCell] = Double.parseDouble(kernel.getValueAt(i, j).toString());

            }

            catch (final NumberFormatException e) {

               m_dCoeffs[iCell] = 1;

            }

            iCell++;

         }

      }

      for (y = 0; (y < iNY) && setProgress(y, iNY); y++) {

         for (x = 0; x < iNX; x++) {

            setNeighborhoodValues(x, y);

            result.setCellValue(x, y, processValues());

         }

         setProgress(y, iNY);

      }

      return !m_Task.isCanceled();

   }

   private void setNeighborhoodValues(final int iX,

                                      final int iY) {

      int x, y;

      int iCell = 0;

      for (y = -1; y < 2; y++) {

         for (x = -1; x < 2; x++) {

            m_dValues[iCell] = m_Window.getCellValueAsDouble(iX + x, iY + y);

            iCell++;

         }

      }

   }

   protected double processValues() {

      int i = 0;

      double dResult = 0;

      for (i = 0; i < m_dValues.length; i++) {

         if (m_dValues[i] != m_dNoData) {

            dResult += (m_dCoeffs[i] * m_dValues[i]);

         }

         else {

            return m_dNoData;

         }

      }

      return dResult;

   }

}