/**
   * Use the GUI results to set up the variables needed to run the algorithm.
   *
   * @return <code>true</code> if parameters set successfully, <code>false</code> otherwise.
   */
  private boolean setVariables() {
    String tmpStr;
    int i;

    int totLength = image.getExtents()[0];

    for (i = 1; i < image.getNDims(); i++) {
      totLength *= image.getExtents()[i];
    }

    tmpStr = greenMergingText.getText();
    mergingDistance = Float.parseFloat(tmpStr);
    if (mergingDistance < 0.0f) {
      MipavUtil.displayError("Merging distance cannot be less than 0");
      greenMergingText.requestFocus();
      greenMergingText.selectAll();
      return false;
    }

    tmpStr = redMinText.getText();
    redMin = Integer.parseInt(tmpStr);

    if (redMin < 1) {
      MipavUtil.displayError("red minimum must be at least 1");
      redMinText.requestFocus();
      redMinText.selectAll();

      return false;
    } else if (redMin > totLength) {
      MipavUtil.displayError("red minimum must not exceed " + totLength);
      redMinText.requestFocus();
      redMinText.selectAll();

      return false;
    }

    tmpStr = redFractionText.getText();
    redFraction = Float.parseFloat(tmpStr);

    if (redFraction <= 0.0f) {
      MipavUtil.displayError("red fraction must be greater than zero");
      redFractionText.requestFocus();
      redFractionText.selectAll();

      return false;
    } else if (redFraction > 1.0f) {
      MipavUtil.displayError("red fraction must not exceed one");
      redFractionText.requestFocus();
      redFractionText.selectAll();

      return false;
    }

    tmpStr = greenMinText.getText();
    greenMin = Integer.parseInt(tmpStr);

    if (greenMin < 1) {
      MipavUtil.displayError("green minimum must be at least 1");
      greenMinText.requestFocus();
      greenMinText.selectAll();

      return false;
    } else if (greenMin > totLength) {
      MipavUtil.displayError("green minimum must not exceed " + totLength);
      greenMinText.requestFocus();
      greenMinText.selectAll();

      return false;
    }

    tmpStr = greenFractionText.getText();
    greenFraction = Float.parseFloat(tmpStr);

    if (greenFraction <= 0.0f) {
      MipavUtil.displayError("green fraction must be greater than zero");
      greenFractionText.requestFocus();
      greenFractionText.selectAll();

      return false;
    } else if (greenFraction > 1.0f) {
      MipavUtil.displayError("green fraction must not exceed one");
      greenFractionText.requestFocus();
      greenFractionText.selectAll();

      return false;
    }

    tmpStr = blueMinText.getText();
    blueMin = Integer.parseInt(tmpStr);
    if (blueMin <= 0) {
      MipavUtil.displayError("Number of blue pixels must be greater than 0");
      blueMinText.requestFocus();
      blueMinText.selectAll();
      return false;
    } else if (blueMin > totLength) {
      MipavUtil.displayError("blue minimum must not exceed " + totLength);
      blueMinText.requestFocus();
      blueMinText.selectAll();

      return false;
    }

    if (oneButton.isSelected()) {
      greenRegionNumber = 1;
    } else if (twoButton.isSelected()) {
      greenRegionNumber = 2;
    } else if (threeButton.isSelected()) {
      greenRegionNumber = 3;
    } else {
      greenRegionNumber = 4;
    }

    twoGreenLevels = twoBox.isSelected();

    tmpStr = blueValueText.getText();
    blueBoundaryFraction = Float.parseFloat(tmpStr);
    if (blueBoundaryFraction < 0.0f) {
      MipavUtil.displayError("Blue boundary fraction cannot be less than 0.0");
      blueValueText.requestFocus();
      blueValueText.selectAll();
      return false;
    } else if (blueBoundaryFraction > 1.0f) {
      MipavUtil.displayError("Blue boundary value cannot be greater than 1.0");
      blueValueText.requestFocus();
      blueValueText.selectAll();
      return false;
    }

    blueSmooth = blueSmoothBox.isSelected();

    tmpStr = interpolationText.getText();
    interpolationDivisor = Float.parseFloat(tmpStr);
    if (interpolationDivisor <= 1.0f) {
      MipavUtil.displayError("Interpolation divisor must be greater than 1");
      interpolationText.requestFocus();
      interpolationText.selectAll();
      return false;
    }

    return true;
  } // end setVariables()