Examples with GvrsElementSpecification org.gridfour.gvrs.GvrsElementSpecification used on opensource projects

Example 1 with GvrsElementSpecification

use of org.gridfour.gvrs.GvrsElementSpecification in project gridfour by gwlucastrig.

the class ExperimentalImageStorage method main.

/**
 * Process the specified file storing it in different image formats
 * as a way of testing data processing concepts for GVRS.
 *
 * @param args the command line arguments, the first of which give the path
 * to the input file
 * @throws java.io.IOException in the event of an unhandled IO exception
 * @throws org.apache.commons.imaging.ImageReadException in the event of an
 * unhandled exception reading an image
 */
public static void main(String[] args) throws IOException, ImageReadException {
    File input = new File(args[0]);
    Date date = new Date();
    SimpleDateFormat sdFormat = new SimpleDateFormat("dd MMM yyyy HH:mm", Locale.getDefault());
    sdFormat.setTimeZone(new SimpleTimeZone(0, "UTC"));
    System.out.format("Processing image from %s%n", input.getName());
    System.out.format("Date/time of test: %s (UTC)%n", sdFormat.format(date));
    System.out.println("");
    long time0, time1;
    // -------------------------------------------------------------
    // Load the specified file to obtain sample data for processing.
    time0 = System.currentTimeMillis();
    BufferedImage bImage = Imaging.getBufferedImage(input);
    time1 = System.currentTimeMillis();
    int width = bImage.getWidth();
    int height = bImage.getHeight();
    int nPixels = width * height;
    // GVRS API uses row, column as grid coordinates
    int nRows = height;
    int nCols = width;
    System.out.println("Image loaded");
    System.out.format("   Width:                 %7d%n", width);
    System.out.format("   Height:                %7d%n", height);
    report(time0, time1, input, nPixels);
    int[] argb = new int[width * height];
    bImage.getRGB(0, 0, width, height, argb, 0, width);
    bImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    bImage.setRGB(0, 0, width, height, argb, 0, width);
    // ---------------------------------------------------------------
    // As a basis for comparison, store the image as a PNG
    // and report the time required to do so.
    File refPNG = new File("ReferenceImage.png");
    if (refPNG.exists()) {
        refPNG.delete();
    }
    time0 = System.currentTimeMillis();
    ImageIO.write(bImage, "PNG", refPNG);
    time1 = System.currentTimeMillis();
    System.out.println("ImageIO writing PNG");
    report(time0, time1, refPNG, nPixels);
    // ---------------------------------------------------------------
    File refJPEG = new File("ReferenceImage.jpg");
    if (refJPEG.exists()) {
        refJPEG.delete();
    }
    time0 = System.currentTimeMillis();
    ImageIO.write(bImage, "JPEG", refJPEG);
    time1 = System.currentTimeMillis();
    System.out.println("ImageIO writing JPEG");
    report(time0, time1, refJPEG, nPixels);
    // Note:
    // In the following code blocks, there are references to the GvrsFile
    // summarize() method.  These are commented out because they would
    // interfere with timing measurements and also because they produce
    // considerable output text which would clutter the report.
    // Note also that calls to flush() are not normally required since
    // GvrsFile performs a flush as part of its close() operation.
    // ---------------------------------------------------------------
    GvrsFileSpecification gvrsFileSpec;
    // The first test stores the specified data in an uncompressed format.
    // This is the fastest option for processing pixel data and is recommended
    // for high-performance processing.
    System.out.println("Storing pixels as integers in uncompressed GVRS file");
    gvrsFileSpec = new GvrsFileSpecification(nRows, nCols, 200, 200);
    GvrsElementSpecification pSpec = new GvrsElementSpecificationInt("pixel");
    gvrsFileSpec.addElementSpecification(pSpec);
    File output0 = new File("IntPixelNoComp.gvrs");
    time0 = System.currentTimeMillis();
    try (GvrsFile gvrs = new GvrsFile(output0, gvrsFileSpec)) {
        gvrs.setTileCacheSize(GvrsCacheSize.Large);
        GvrsElement pixel = gvrs.getElement("pixel");
        for (int iRow = 0; iRow < nRows; iRow++) {
            for (int iCol = 0; iCol < nCols; iCol++) {
                int index = iRow * nCols + iCol;
                pixel.writeValueInt(iRow, iCol, argb[index]);
            }
        }
    }
    time1 = System.currentTimeMillis();
    report(time0, time1, output0, nPixels);
    // ---------------------------------------------------------------
    // Store the pixels in compressed format, but do not make any special
    // processing to improve the results. In most cases, compression using
    // this approach will not yield a substantial saving in storage.
    System.out.println("Storing pixels as integers in compressed GVRS file");
    File output1 = new File("IntPixelComp.gvrs");
    gvrsFileSpec.setDataCompressionEnabled(true);
    LsCodecUtility.addLsopToSpecification(gvrsFileSpec, true);
    time0 = System.currentTimeMillis();
    try (GvrsFile gvrs = new GvrsFile(output1, gvrsFileSpec)) {
        gvrs.setTileCacheSize(GvrsCacheSize.Large);
        GvrsElement pixel = gvrs.getElement("pixel");
        for (int iRow = 0; iRow < nRows; iRow++) {
            for (int iCol = 0; iCol < nCols; iCol++) {
                int index = iRow * nCols + iCol;
                pixel.writeValueInt(iRow, iCol, argb[index]);
            }
        }
    // gvrs.flush();
    // gvrs.summarize(System.out, true);
    }
    time1 = System.currentTimeMillis();
    report(time0, time1, output1, nPixels);
    // ---------------------------------------------------------------
    // Separate the pixels into separate RGB components, store each component
    // in a separate GVRS Element. This approach should improve compression
    // ratios.
    System.out.println("Storing RGB components in compressed GVRS file");
    gvrsFileSpec = new GvrsFileSpecification(nRows, nCols, 200, 200);
    gvrsFileSpec.setDataCompressionEnabled(true);
    LsCodecUtility.addLsopToSpecification(gvrsFileSpec, true);
    gvrsFileSpec.addElementSpecification(new GvrsElementSpecificationInt("r"));
    gvrsFileSpec.addElementSpecification(new GvrsElementSpecificationInt("g"));
    gvrsFileSpec.addElementSpecification(new GvrsElementSpecificationInt("b"));
    File output2 = new File("PixelsCompRGB.gvrs");
    gvrsFileSpec.setDataCompressionEnabled(true);
    time0 = System.currentTimeMillis();
    try (GvrsFile gvrs = new GvrsFile(output2, gvrsFileSpec)) {
        gvrs.setTileCacheSize(GvrsCacheSize.Large);
        GvrsElement rElem = gvrs.getElement("r");
        GvrsElement gElem = gvrs.getElement("g");
        GvrsElement bElem = gvrs.getElement("b");
        for (int iRow = 0; iRow < nRows; iRow++) {
            for (int iCol = 0; iCol < nCols; iCol++) {
                int rgb = argb[iRow * nCols + iCol];
                int r = (rgb >> 16) & 0xff;
                int g = (rgb >> 8) & 0xff;
                int b = rgb & 0xff;
                rElem.writeValueInt(iRow, iCol, r);
                gElem.writeValueInt(iRow, iCol, g);
                bElem.writeValueInt(iRow, iCol, b);
            }
        }
    // gvrs.flush();
    // gvrs.summarize(System.out, true);
    }
    time1 = System.currentTimeMillis();
    report(time0, time1, output2, nPixels);
    // ---------------------------------------------------------------
    // Convert RGB color values to the YCoCg-R color space before storage.
    // For photographic images, this approach should further reduce storage
    // size.  For charts, graphs, line drawings, and other such graphic art
    // this approach will usually not produce a gain and sometimes degrades
    // compression.
    System.out.println("Storing YCoCg-R components in compressed GVRS file");
    gvrsFileSpec = new GvrsFileSpecification(nRows, nCols, 200, 200);
    gvrsFileSpec.setDataCompressionEnabled(true);
    LsCodecUtility.addLsopToSpecification(gvrsFileSpec, true);
    gvrsFileSpec.addElementSpecification(new GvrsElementSpecificationInt("Y"));
    gvrsFileSpec.addElementSpecification(new GvrsElementSpecificationInt("Co"));
    gvrsFileSpec.addElementSpecification(new GvrsElementSpecificationInt("Cg"));
    File output3 = new File("PixelsCompYCoCg.gvrs");
    time0 = System.currentTimeMillis();
    try (GvrsFile gvrs = new GvrsFile(output3, gvrsFileSpec)) {
        gvrs.setTileCacheSize(GvrsCacheSize.Large);
        GvrsElement YElem = gvrs.getElement("Y");
        GvrsElement CoElem = gvrs.getElement("Co");
        GvrsElement CgElem = gvrs.getElement("Cg");
        for (int iRow = 0; iRow < nRows; iRow++) {
            for (int iCol = 0; iCol < nCols; iCol++) {
                int rgb = argb[iRow * nCols + iCol];
                int r = (rgb >> 16) & 0xff;
                int g = (rgb >> 8) & 0xff;
                int b = rgb & 0xff;
                int Co = r - b;
                // Co>>1 is equivalent to Co/2
                int tmp = b + (Co >> 1);
                int Cg = g - tmp;
                int Y = tmp + (Cg >> 1);
                YElem.writeValueInt(iRow, iCol, Y);
                CoElem.writeValueInt(iRow, iCol, Co);
                CgElem.writeValueInt(iRow, iCol, Cg);
            }
        }
    // gvrs.flush();
    // gvrs.summarize(System.out, true);
    }
    time1 = System.currentTimeMillis();
    report(time0, time1, output3, nPixels);
    // ---------------------------------------------------------------
    // Finally, test the time required to load a YCoCg image
    // Then write the results to a JPEG file for inspection.
    // This test code also illustrates how the YCoCg values may be
    // mapped back to RGB.
    System.out.println("Testing time to read the YCoCg compressed file");
    time0 = System.currentTimeMillis();
    try (GvrsFile gvrs = new GvrsFile(output3, "r")) {
        gvrs.setTileCacheSize(GvrsCacheSize.Large);
        GvrsElement YElem = gvrs.getElement("Y");
        GvrsElement CoElem = gvrs.getElement("Co");
        GvrsElement CgElem = gvrs.getElement("Cg");
        for (int iRow = 0; iRow < nRows; iRow++) {
            for (int iCol = 0; iCol < nCols; iCol++) {
                int Y = YElem.readValueInt(iRow, iCol);
                int Co = CoElem.readValueInt(iRow, iCol);
                int Cg = CgElem.readValueInt(iRow, iCol);
                int tmp = Y - (Cg >> 1);
                int g = Cg + tmp;
                int b = tmp - (Co >> 1);
                int r = b + Co;
                argb[iRow * nCols + iCol] = (((0xff00 | r) << 8 | g) << 8) | b;
            }
        }
    }
    time1 = System.currentTimeMillis();
    report(time0, time1, output3, nPixels);
    File resultsJPEG = new File("ResultsForInspection.jpg");
    if (resultsJPEG.exists()) {
        resultsJPEG.delete();
    }
    bImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    bImage.setRGB(0, 0, width, height, argb, 0, width);
    time0 = System.currentTimeMillis();
    ImageIO.write(bImage, "JPEG", resultsJPEG);
    time1 = System.currentTimeMillis();
    System.out.println("ImageIO writing JPEG");
}

Example 2 with GvrsElementSpecification

use of org.gridfour.gvrs.GvrsElementSpecification in project gridfour by gwlucastrig.

the class PackageData method process.

void process(PrintStream ps, TestOptions options, String[] args) throws IOException {
    // The packaging of data in a Gvrs file can be thought of in terms of
    // the steps shown below.
    // 
    // 0.  Obtain descriptive parameters about source data.  In this
    // case, the application is packing data from a NetCDF source
    // and most of the descriptive parameters follow the pattern
    // established in the earlier ExtractData.java demonstration
    // 
    // 1.  Define the fixed metadata about the file (it's dimensions,
    // data type, tile organization, etc.) using a GvrsFileSpecification
    // object.
    // 
    // 2.  Open a new GvrsFile object using the settings created in step 1.
    // Adjust any run-time parameters (such as the tile-cache size)
    // according to the needs of the application.
    // 
    // 3.  Extract the data from its source and store in the Gvrs file.
    // 
    ps.format("%nGvrs Packaging Application for NetCDF-format Global DEM files%n");
    Locale locale = Locale.getDefault();
    Date date = new Date();
    SimpleDateFormat sdFormat = new SimpleDateFormat("dd MMM yyyy HH:mm z", locale);
    ps.format("Date of Execution: %s%n", sdFormat.format(date));
    String inputPath = options.getInputFile().getPath();
    File outputFile = options.getOutputFile();
    if (outputFile == null) {
        ps.format("Missing specification for output file%n");
        ps.format("Packaging application terminated%n");
        return;
    }
    ps.format("Input file:  %s%n", inputPath);
    ps.format("Output file: %s%n", outputFile.getPath());
    boolean[] matched = new boolean[args.length];
    boolean useLsop = options.scanBooleanOption(args, "-lsop", matched, false);
    // Open the NetCDF file -----------------------------------
    ps.println("Opening NetCDF input file");
    NetcdfFile ncfile = NetcdfFile.open(inputPath);
    // Identify which Variable instances carry information about the
    // geographic (latitude/longitude) coordinate system and also which
    // carry information for elevation and bathymetry.
    // the Variable that carries row-latitude information
    Variable lat;
    // the Variable that carries column-longitude information
    Variable lon;
    // the variable that carries elevation and bathymetry
    Variable z;
    lat = ncfile.findVariable("lat");
    lon = ncfile.findVariable("lon");
    z = ncfile.findVariable("elevation");
    int[] tileSize;
    // Use the input file name to format a product label
    File inputFile = new File(inputPath);
    String productLabel = inputFile.getName();
    if (productLabel.toLowerCase().endsWith(".nc")) {
        productLabel = productLabel.substring(0, productLabel.length() - 3);
    }
    if (lat == null) {
        // ETOPO1 specification
        tileSize = options.getTileSize(90, 120);
        lat = ncfile.findVariable("y");
        lon = ncfile.findVariable("x");
        z = ncfile.findVariable("z");
    } else {
        tileSize = options.getTileSize(90, 120);
    }
    if (lat == null || lon == null || z == null) {
        throw new IllegalArgumentException("Input does not contain valid lat,lon, and elevation Variables");
    }
    // using the variables from above, extract coordinate system
    // information for the product and print it to the output.
    ExtractionCoordinates extractionCoords = new ExtractionCoordinates(lat, lon);
    extractionCoords.summarizeCoordinates(ps);
    // Get the dimensions of the raster (grid) elevation/bathymetry data.
    // should be 1.
    int rank = z.getRank();
    int[] shape = z.getShape();
    int nRows = shape[0];
    int nCols = shape[1];
    ps.format("Rows:      %8d%n", nRows);
    ps.format("Columns:   %8d%n", nCols);
    int nRowsInTile = tileSize[0];
    int nColsInTile = tileSize[1];
    // Initialize the specification used to initialize the Gvrs file -------
    GvrsFileSpecification spec = new GvrsFileSpecification(nRows, nCols, nRowsInTile, nColsInTile);
    spec.setLabel(productLabel);
    // Initialize the data type.  If a zScale option was specified,
    // use integer-coded floats.  Otherwise, pick the data type
    // based on whether the NetCDF file gives integral or floating point
    // data.
    boolean isZScaleSpecified = options.isZScaleSpecified();
    float zScale = (float) options.getZScale();
    float zOffset = (float) options.getZOffset();
    // data type from NetCDF file
    DataType sourceDataType = z.getDataType();
    GvrsElementSpecification elementSpec = null;
    GvrsElementType gvrsDataType;
    if (isZScaleSpecified) {
        // the options define our data type
        int encodedLimitDepth = (int) ((LIMIT_DEPTH - zOffset) * zScale);
        int encodedLimitElev = (int) ((LIMIT_ELEVATION - zOffset) * zScale);
        elementSpec = new GvrsElementSpecificationIntCodedFloat("z", zScale, zOffset, encodedLimitDepth, encodedLimitElev, Integer.MIN_VALUE, true);
        spec.addElementSpecification(elementSpec);
        gvrsDataType = GvrsElementType.INT_CODED_FLOAT;
    } else if (sourceDataType.isIntegral()) {
        elementSpec = new GvrsElementSpecificationShort("z", LIMIT_DEPTH, LIMIT_ELEVATION, FILL_VALUE);
        spec.addElementSpecification(elementSpec);
        gvrsDataType = GvrsElementType.SHORT;
    } else {
        elementSpec = new GvrsElementSpecificationFloat("z", LIMIT_DEPTH, LIMIT_ELEVATION, Float.NaN);
        spec.addElementSpecification(elementSpec);
        gvrsDataType = GvrsElementType.FLOAT;
    }
    elementSpec.setDescription("Elevation (positive values) or depth (negative), in meters");
    elementSpec.setUnitOfMeasure("m");
    // Example with special character
    elementSpec.setLabel("die H\u00f6henlage");
    ps.println("Source date type " + sourceDataType + ", stored as " + gvrsDataType);
    ps.println("");
    // Determine whether data compression is used -------------------
    boolean compressionEnabled = options.isCompressionEnabled();
    spec.setDataCompressionEnabled(compressionEnabled);
    boolean checksumsEnalbed = options.isChecksumComputationEnabled();
    spec.setChecksumEnabled(checksumsEnalbed);
    boolean bigAddressSpaceEnabled = options.isBigAddressSpaceEnabled();
    spec.setExtendedFileSizeEnabled(bigAddressSpaceEnabled);
    double[] geoCoords = extractionCoords.getGeographicCoordinateBounds();
    spec.setGeographicCoordinates(geoCoords[0], geoCoords[1], geoCoords[2], geoCoords[3]);
    // Check to verify that the geographic coordinates and grid coordinate
    // are correctly implemented. This test is not truly part of the packaging
    // process (since it should always work), but is included here as a
    // diagnostic.
    extractionCoords.checkSpecificationTransform(ps, spec);
    // is enabled and the data type is integral.
    if (useLsop) {
        LsCodecUtility.addLsopToSpecification(spec, false);
    }
    // Create the output file and store the content from the input file.
    if (outputFile.exists()) {
        ps.println("Output file exists. Removing old file");
        boolean status = outputFile.delete();
        if (!status) {
            ps.println("Removal attempt failed");
            return;
        }
    }
    ps.println("Begin processing");
    double zMin = Double.POSITIVE_INFINITY;
    double zMax = Double.NEGATIVE_INFINITY;
    double zSum = 0;
    long nSum = 0;
    try (GvrsFile gvrs = new GvrsFile(outputFile, spec)) {
        gvrs.writeMetadata(GvrsMnc.Copyright, "This data is in the public domain and may be used free of charge");
        gvrs.writeMetadata(GvrsMnc.TermsOfUse, "This data should not be used for navigation");
        GvrsElement zElement = gvrs.getElement("z");
        gvrs.setTileCacheSize(GvrsCacheSize.Large);
        storeGeoreferencingInformation(gvrs);
        // Initialize data-statistics collection ---------------------------
        // we happen to know the range of values for the global DEM a-priori.
        // it ranges from about -11000 to 8650.  This allows us to tabulate counts
        // of which values we find in the data source.  We can use this information
        // to estimate the entropy of the source data and make a realistic
        // assessment of how many bytes would be needed to store them.
        InputDataStatCollector stats = new InputDataStatCollector(-11000, 8650, zScale);
        int[] readOrigin = new int[rank];
        int[] readShape = new int[rank];
        // -----------------------------------------------------------------
        // Package the data
        long time0 = System.currentTimeMillis();
        for (int iRow = 0; iRow < nRows; iRow++) {
            if (iRow % 1000 == 999) {
                long time1 = System.currentTimeMillis();
                double deltaT = time1 - time0;
                // rows per millis
                double rate = (iRow + 1) / deltaT;
                int nRemaining = nRows - iRow;
                long remainingT = (long) (nRemaining / rate);
                Date d = new Date(time1 + remainingT);
                ps.format("Completed %d rows, %4.1f%% of total, est completion at %s%n", iRow + 1, 100.0 * (double) iRow / (nRows - 1.0), d);
                ps.flush();
            }
            int row0 = iRow;
            int col0 = 0;
            readOrigin[0] = row0;
            readOrigin[1] = col0;
            readShape[0] = 1;
            readShape[1] = nCols;
            // happen in this application unless the input file is corrupt.
            try {
                Array array = z.read(readOrigin, readShape);
                // and store it in the Gvrs file.
                switch(gvrsDataType) {
                    case INTEGER:
                    case SHORT:
                        for (int iCol = 0; iCol < nCols; iCol++) {
                            int sample = array.getInt(iCol);
                            zElement.writeValueInt(iRow, iCol, sample);
                            stats.addSample(sample);
                            if (sample < zMin) {
                                zMin = sample;
                            }
                            if (sample > zMax) {
                                zMax = sample;
                            }
                            zSum += sample;
                            nSum++;
                        }
                        break;
                    case INT_CODED_FLOAT:
                    case FLOAT:
                    default:
                        for (int iCol = 0; iCol < nCols; iCol++) {
                            float sample = array.getFloat(iCol);
                            zElement.writeValue(iRow, iCol, sample);
                            stats.addSample(sample);
                            if (sample < zMin) {
                                zMin = sample;
                            }
                            if (sample > zMax) {
                                zMax = sample;
                            }
                            zSum += sample;
                            nSum++;
                        }
                }
            } catch (InvalidRangeException irex) {
                throw new IOException(irex.getMessage(), irex);
            }
        }
        gvrs.flush();
        long time1 = System.currentTimeMillis();
        double timeToProcess = (time1 - time0) / 1000.0;
        ps.format("Finished processing file in %4.1f seconds%n", timeToProcess);
        ps.format("Entropy for input data %4.1f bits/sample%n", stats.getEntropy());
        long outputSize = outputFile.length();
        long nCells = (long) nRows * (long) nCols;
        double bitsPerSymbol = 8.0 * (double) outputSize / (double) nCells;
        ps.format("Storage used (including overhead) %6.4f bits/sample%n", bitsPerSymbol);
        ps.format("%nSummary of file content and packaging actions------------%n");
        gvrs.summarize(ps, true);
        ps.format("Range of z values:%n");
        ps.format("  Min z: %8.3f%n", zMin);
        ps.format("  Max z: %8.3f%n", zMax);
        ps.format("  Avg z: %8.3f%n", zSum / (nSum > 0 ? nSum : 1));
    }
    // to those of the source data.
    if (options.isVerificationEnabled()) {
        int[] readOrigin = new int[rank];
        int[] readShape = new int[rank];
        ps.println("\nTesting product for data consistency with source");
        ps.println("Opening gvrs file for reading");
        long time0 = System.currentTimeMillis();
        try (GvrsFile gvrs = new GvrsFile(outputFile, "r")) {
            long time1 = System.currentTimeMillis();
            ps.println("Opening complete in " + (time1 - time0) + " ms");
            GvrsFileSpecification testSpec = gvrs.getSpecification();
            String testLabel = testSpec.getLabel();
            ps.println("Label:     " + testLabel);
            GvrsMetadata m = gvrs.readMetadata("Copyright", 0);
            if (m != null) {
                ps.println("Copyright: " + m.getString());
            }
            GvrsElement zElement = gvrs.getElement("z");
            ps.println("Element:   " + zElement.getName() + ", " + zElement.getDescription());
            gvrs.setTileCacheSize(GvrsCacheSize.Large);
            for (int iRow = 0; iRow < nRows; iRow++) {
                if (iRow % 10000 == 9999) {
                    time1 = System.currentTimeMillis();
                    double deltaT = time1 - time0;
                    // rows per millis
                    double rate = (iRow + 1) / deltaT;
                    int nRemaining = nRows - iRow;
                    long remainingT = (long) (nRemaining / rate);
                    Date d = new Date(time1 + remainingT);
                    ps.format("Completed %d rows, %4.1f%% of total, est completion at %s%n", iRow + 1, 100.0 * (double) iRow / (nRows - 1.0), d);
                    ps.flush();
                }
                int row0 = iRow;
                int col0 = 0;
                readOrigin[0] = row0;
                readOrigin[1] = col0;
                readShape[0] = 1;
                readShape[1] = nCols;
                try {
                    Array array = z.read(readOrigin, readShape);
                    switch(gvrsDataType) {
                        case INTEGER:
                            for (int iCol = 0; iCol < nCols; iCol++) {
                                int sample = array.getInt(iCol);
                                int test = zElement.readValueInt(iRow, iCol);
                                if (sample != test) {
                                    ps.println("Failure at " + iRow + ", " + iCol);
                                    test = zElement.readValueInt(iRow, iCol);
                                    System.exit(-1);
                                }
                            }
                            break;
                        case INT_CODED_FLOAT:
                            for (int iCol = 0; iCol < nCols; iCol++) {
                                double sample = array.getDouble(iCol);
                                int iSample = (int) ((sample - zOffset) * zScale + 0.5);
                                float fSample = iSample / zScale + zOffset;
                                float test = zElement.readValue(iRow, iCol);
                                double delta = Math.abs(fSample - test);
                                if (delta > 1.01 / zScale) {
                                    ps.println("Failure at " + iRow + ", " + iCol);
                                    System.exit(-1);
                                }
                            }
                            break;
                        case FLOAT:
                        default:
                            for (int iCol = 0; iCol < nCols; iCol++) {
                                float sample = array.getFloat(iCol);
                                float test = zElement.readValue(iRow, iCol);
                                if (sample != test) {
                                    ps.println("Failure at " + iRow + ", " + iCol);
                                    test = zElement.readValueInt(iRow, iCol);
                                    System.exit(-1);
                                }
                            }
                    }
                } catch (InvalidRangeException irex) {
                    throw new IOException(irex.getMessage(), irex);
                }
            }
            time1 = System.currentTimeMillis();
            ps.println("Exhaustive cross check complete in " + (time1 - time0) + " ms");
            gvrs.summarize(ps, false);
        }
    }
    ncfile.close();
}