public void actionPerformed(ActionEvent e) {
      Button b = (Button) e.getSource();
      if (b == null) return;

      boolean imageThere = checkImage();

      if (imageThere) {
        if (b == originalB) {
          reset(imp, ip);
          filteredB.setEnabled(true);
        } else if (b == filteredB) {
          apply(imp, ip);
        } else if (b == sampleB) {
          reset(imp, ip);
          sample();
          apply(imp, ip);
        } else if (b == stackB) {
          applyStack();
        } else if (b == helpB) {
          IJ.showMessage(
              "Help",
              "Threshold Colour  v1.0\n \n"
                  + "Modification of Bob Dougherty's BandPass2 plugin by G.Landini to\n"
                  + "threshold 24 bit RGB images based on Hue, Saturation and Brightness\n"
                  + "or Red, Green and Blue components.\n \n"
                  + "Pass: Band-pass filter (anything within range is displayed).\n \n"
                  + "Stop: Band-reject filter (anything within range is NOT displayed).\n \n"
                  + "Original: Shows the original image and updates the buffer when\n"
                  + " switching to another image.\n \n"
                  + "Filtered: Shows the filtered image.\n \n"
                  + "Stack: Processes the rest of the slices in the stack (if any)\n"
                  + " using the current settings.\n \n"
                  + "Threshold: Shows the object/background in the foreground and\n"
                  + " background colours selected in the ImageJ toolbar.\n \n"
                  + "Invert: Swaps the fore/background colours.\n \n"
                  + "Sample: (experimental) Sets the ranges of the filters based on the\n"
                  + " pixel value componentd in a rectangular, user-defined, ROI.\n \n"
                  + "HSB RGB: Selects HSB or RGB space and resets all the filters.\n \n"
                  + "Note that the \'thresholded\' image is RGB, not 8 bit grey.");
        }
        updatePlot();
        updateLabels();
        imp.updateAndDraw();
      } else {
        IJ.beep();
        IJ.showStatus("No Image");
      }
      notify();
    }
 private void showioerror() {
   IJ.showMessage("Error in file io");
 }
  private void geterrors() {
    GenericDialog gd = new GenericDialog("Options");
    float conf = 0.67f;
    gd.addNumericField("Confidence Limit", (int) (conf * 100.0f), 5, 10, null);
    gd.addChoice("Error Parameter", paramsnames, paramsnames[0]);
    double spacing = 0.01;
    gd.addNumericField("Chi^2 plot spacing (% of value)?", spacing * 100.0, 2, 10, null);
    boolean globalerror = false;
    gd.addCheckbox("Global Fit Error?", globalerror);
    int dataset = 0;
    gd.addNumericField("Data Set (for Global Error)", dataset, 0);
    gd.showDialog();
    if (gd.wasCanceled()) {
      return;
    }
    conf = 0.01f * (float) gd.getNextNumber();
    int paramindex = (int) gd.getNextChoiceIndex();
    spacing = 0.01 * gd.getNextNumber();
    globalerror = gd.getNextBoolean();
    dataset = (int) gd.getNextNumber();

    if (globalerror) {
      support_plane_errors erclass = new support_plane_errors(this, 0.0001, 50, true, 0.1);
      int[] erindeces = {paramindex, dataset};
      // need to set up all the matrices
      int nsel = 0;
      int nparams = 11;
      for (int i = 0; i < ncurves; i++) {
        if (include[i]) {
          nsel++;
        }
      }
      double[][] params = new double[nsel][nparams];
      String[][] tempformulas = new String[nsel][nparams];
      double[][][] constraints = new double[2][nsel][nparams];
      int[][] vflmatrix = new int[nsel][nparams];

      float[][] tempdata = new float[nsel][xpts * ypts];
      float[][] tempweights = new float[nsel][xpts * ypts];

      int nfit = 0;
      int counter = 0;
      for (int i = 0; i < ncurves; i++) {
        if (include[i]) {
          for (int j = 0; j < nparams; j++) {
            params[counter][j] = globalparams[i][j];
            tempformulas[counter][j] = globalformulas[i][j];
            constraints[0][counter][j] = globalconstraints[0][i][j];
            constraints[1][counter][j] = globalconstraints[1][i][j];
            vflmatrix[counter][j] = globalvflmatrix[i][j];
            if (vflmatrix[counter][j] == 0 || (j == 0 && vflmatrix[counter][j] == 2)) {
              nfit++;
            }
          }
          for (int j = 0; j < xpts; j++) {
            for (int k = 0; k < ypts; k++) {
              tempdata[counter][j + k * xpts] = (float) ((double) pch[i][j][k] / (double) nmeas[i]);
              tempweights[counter][j + k * xpts] = weights[i][j][k];
            }
          }
          counter++;
        }
      }
      int dofnum = xpts * ypts * nsel - (nfit - 1) - 1;
      int dofden = xpts * ypts * nsel - nfit - 1;
      // double flim=FLimit(dofnum,dofden,(double)conf);
      double flim = (new jdist()).FLimit(dofnum, dofden, (double) conf);
      IJ.log("FLimit = " + (float) flim);
      if (flim == Double.NaN && flim < 1.0) {
        IJ.showMessage("Invalid Limiting F Value");
        return;
      }
      double truespacing = Math.abs(params[erindeces[1]][erindeces[0]] * spacing);
      double[][] c2plot =
          erclass.geterrorsglobal(
              params,
              vflmatrix,
              tempformulas,
              paramsnames,
              constraints,
              tempdata,
              tempweights,
              flim,
              truespacing,
              erindeces);
      IJ.log("upper limit = " + c2plot[1][0] + " lower limit = " + c2plot[0][0]);
      int templength = c2plot[0].length;
      float[][] c2plotf = new float[2][templength - 1];
      for (int i = 0; i < (templength - 1); i++) {
        c2plotf[0][i] = (float) c2plot[0][i + 1];
        c2plotf[1][i] = (float) c2plot[1][i + 1];
      }
      new PlotWindow4(
              "c2 plot",
              paramsnames[paramindex] + "[" + dataset + "]",
              "Chi^2",
              c2plotf[0],
              c2plotf[1])
          .draw();
    } else {
      support_plane_errors erclass = new support_plane_errors(this, 0.0001, 50, false, 0.1);
      int errindex = paramindex;

      float[] tempdata = new float[xpts * ypts];
      float[] tempweights = new float[xpts * ypts];
      for (int i = 0; i < xpts; i++) {
        for (int j = 0; j < ypts; j++) {
          tempdata[i + j * xpts] = (float) ((double) avg[i][j] / (double) nmeas[ncurves]);
          tempweights[i + j * xpts] = avgweights[i][j];
        }
      }

      int nfit = 0;
      for (int i = 0; i < 7; i++) {
        if (avgfixes[i] == 0) {
          nfit++;
        }
      }
      int dofnum = xpts * ypts - (nfit - 1) - 1;
      int dofden = xpts * ypts - nfit - 1;
      double flim = (new jdist()).FLimit(dofnum, dofden, (double) conf);
      IJ.log("FLimit = " + (float) flim);
      if (flim == Double.NaN && flim < 1.0) {
        IJ.showMessage("Invalid Limiting F Value");
        return;
      }
      double truespacing = Math.abs(avgparams[errindex] * spacing);
      double[][] c2plot =
          erclass.geterrors(
              avgparams,
              avgfixes,
              avgconstraints,
              tempdata,
              tempweights,
              flim,
              truespacing,
              errindex);
      IJ.log("upper limit = " + c2plot[1][0] + " lower limit = " + c2plot[0][0]);
      int templength = c2plot[0].length;
      float[][] c2plotf = new float[2][templength - 1];
      for (int i = 0; i < (templength - 1); i++) {
        c2plotf[0][i] = (float) c2plot[0][i + 1];
        c2plotf[1][i] = (float) c2plot[1][i + 1];
      }
      new PlotWindow4("c2 plot", paramsnames[errindex], "Chi^2", c2plotf[0], c2plotf[1]).draw();
    }
  }
    void sample() {
      byte[] hsSource, ssSource, bsSource;
      // ImageProcessor ip2;
      // ip2 = imp.getProcessor();
      Rectangle myroi = ip.getRoi();
      int swidth = myroi.width;
      int sheight = myroi.height;
      int sy = myroi.y;
      int sx = myroi.x;
      if (swidth == width && sheight == height) {
        IJ.showMessage("Select a rectangular ROI");
        IJ.beep();
        return;
      }

      IJ.run("Select None");

      int snumPixels = swidth * sheight;

      hsSource = new byte[snumPixels];
      ssSource = new byte[snumPixels];
      bsSource = new byte[snumPixels];

      int[] pixs = new int[snumPixels];
      int[] bin = new int[256];

      int counter = 0, pi = 0, rangePassH = 0, rangeStopH = 0, rangePassL = 0, rangeStopL = 0, i, j;

      for (i = sy; i < sy + sheight; i++) {
        for (j = sx; j < sx + swidth; j++) {
          pixs[counter++] = ip.getPixel(j, i);
        }
      }

      // Get hsb or rgb from roi.
      ColorProcessor cp2 = new ColorProcessor(swidth, sheight, pixs);

      int iminhue = 256, imaxhue = -1, iminsat = 256, imaxsat = -1, iminbri = 256, imaxbri = -1;
      int iminred = 256, imaxred = -1, imingre = 256, imaxgre = -1, iminblu = 256, imaxblu = -1;

      if (isRGB) cp2.getRGB(hsSource, ssSource, bsSource);
      else cp2.getHSB(hsSource, ssSource, bsSource);

      for (i = 0; i < snumPixels; i++) {
        bin[hsSource[i] & 255] = 1;
        if ((hsSource[i] & 255) > imaxhue) imaxhue = (hsSource[i] & 255);
        if ((hsSource[i] & 255) < iminhue) iminhue = (hsSource[i] & 255);
        if ((ssSource[i] & 255) > imaxsat) imaxsat = (ssSource[i] & 255);
        if ((ssSource[i] & 255) < iminsat) iminsat = (ssSource[i] & 255);
        if ((bsSource[i] & 255) > imaxbri) imaxbri = (bsSource[i] & 255);
        if ((bsSource[i] & 255) < iminbri) iminbri = (bsSource[i] & 255);
        // IJ.showMessage("h:"+minhue+"H:"+maxhue+"s:"+minsat+"S:"+maxsat+"b:"+minbri+"B:"+maxbri);
      }

      if (!isRGB) { // get pass or stop filter whichever has a narrower range
        for (i = 0; i < 256; i++) {
          if (bin[i] > 0) {
            rangePassL = i;
            break;
          }
        }
        for (i = 255; i >= 0; i--) {
          if (bin[i] > 0) {
            rangePassH = i;
            break;
          }
        }
        for (i = 0; i < 256; i++) {
          if (bin[i] == 0) {
            rangeStopL = i;
            break;
          }
        }
        for (i = 255; i >= 0; i--) {
          if (bin[i] == 0) {
            rangeStopH = i;
            break;
          }
        }
        if ((rangePassH - rangePassL) < (rangeStopH - rangeStopL)) {
          bandPassH.setState(true);
          bandStopH.setState(false);
          iminhue = rangePassL;
          imaxhue = rangePassH;
        } else {
          bandPassH.setState(false);
          bandStopH.setState(true);
          iminhue = rangeStopL;
          imaxhue = rangeStopH;
        }
      } else {
        bandPassH.setState(true);
        bandStopH.setState(false);
      }

      adjustMinHue(iminhue);
      minSlider.setValue(iminhue);
      adjustMaxHue(imaxhue);
      maxSlider.setValue(imaxhue);
      adjustMinSat(iminsat);
      minSlider2.setValue(iminsat);
      adjustMaxSat(imaxsat);
      maxSlider2.setValue(imaxsat);
      adjustMinBri(iminbri);
      minSlider3.setValue(iminbri);
      adjustMaxBri(imaxbri);
      maxSlider3.setValue(imaxbri);
      originalB.setEnabled(true);
      // IJ.showStatus("done");
    }