ScalarQuantizationBenchmark.java

package azgracompress.benchmark;

import azgracompress.U16;
import azgracompress.cli.ParsedCliOptions;
import azgracompress.data.V3i;
import azgracompress.quantization.QTrainIteration;
import azgracompress.cache.QuantizationCacheManager;
import azgracompress.quantization.scalar.LloydMaxU16ScalarQuantization;
import azgracompress.quantization.scalar.SQCodebook;
import azgracompress.quantization.scalar.ScalarQuantizer;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;

public class ScalarQuantizationBenchmark extends BenchmarkBase {
    public ScalarQuantizationBenchmark(final String inputFile,
                                       final String outputDirectory,
                                       final int[] planes,
                                       final V3i rawImageDims) {
        super(inputFile, outputDirectory, planes, rawImageDims);
    }

    public ScalarQuantizationBenchmark(final ParsedCliOptions options) {
        super(options);
    }


    @Override
    public void startBenchmark() {
        if (planes.length < 1) {
            return;
        }
        boolean dirCreated = new File(this.outputDirectory).mkdirs();
        System.out.println(String.format("|CODEBOOK| = %d", codebookSize));
        ScalarQuantizer quantizer = null;
        if (hasCacheFolder) {
            System.out.println("Loading codebook from cache");
            QuantizationCacheManager cacheManager = new QuantizationCacheManager(cacheFolder);
            final SQCodebook codebook = cacheManager.loadSQCodebook(inputFile, codebookSize);

            if (codebook == null) {
                System.err.println("Failed to read quantization values from cache file.");
                return;
            }

            quantizer = new ScalarQuantizer(codebook);
            System.out.println("Created quantizer from cache");
        } else if (useMiddlePlane) {
            final int middlePlaneIndex = rawImageDims.getZ() / 2;
            final int[] middlePlaneData = loadPlaneData(middlePlaneIndex);
            if (middlePlaneData.length == 0) {
                System.err.println("Failed to load middle plane data.");
                return;
            }
            quantizer = trainLloydMaxQuantizer(middlePlaneData, codebookSize);
            System.out.println("Created quantizer from middle plane.");
        }

        for (final int planeIndex : planes) {
            System.out.println(String.format("Loading plane %d ...", planeIndex));
            // NOTE(Moravec): Actual planeIndex is zero based.
            final int[] planeData = loadPlaneData(planeIndex);
            if (planeData.length == 0) {
                System.err.println(String.format("Failed to load plane %d data. Skipping plane.", planeIndex));
                return;
            }

            if (!hasGeneralQuantizer) {
                quantizer = trainLloydMaxQuantizer(planeData, codebookSize);
                System.out.println("Created plane quantizer");
            }

            if (quantizer == null) {
                System.err.println("Failed to initialize scalar quantizer.");
                return;
            }

            // TODO(Moravec): Add huffman coding.

            final String quantizedFile = String.format(QUANTIZED_FILE_TEMPLATE, planeIndex, codebookSize);
            final String diffFile = String.format(DIFFERENCE_FILE_TEMPLATE, planeIndex, codebookSize);
            final String absoluteDiffFile = String.format(ABSOLUTE_DIFFERENCE_FILE_TEMPLATE,
                                                          planeIndex,
                                                          codebookSize);

            final int[] quantizedData = quantizer.quantize(planeData);

            if (!saveQuantizedPlaneData(quantizedData, quantizedFile)) {
                System.err.println("Failed to save quantized plane.");
                return;
            }

            saveDifference(planeData, quantizedData, diffFile, absoluteDiffFile);
        }
    }

    private void saveCentroids(final int[] centroids, final String centroidsFile) {
        final String outFile = getFileNamePathIntoOutDir(centroidsFile);
        try {
            FileOutputStream fileStream = new FileOutputStream(outFile);
            OutputStreamWriter writer = new OutputStreamWriter(fileStream);

            StringBuilder sb = new StringBuilder();


            for (final int entry : centroids) {
                sb.append(entry);
                sb.append('\n');
            }

            writer.write(sb.toString());

            writer.flush();
            fileStream.flush();
            fileStream.close();
        } catch (IOException ioE) {
            ioE.printStackTrace();
            System.err.println("Failed to save codebook vectors.");
        }
    }

    private ScalarQuantizer trainLloydMaxQuantizer(final int[] data, final int codebookSize) {
        LloydMaxU16ScalarQuantization lloydMax = new LloydMaxU16ScalarQuantization(data, codebookSize, workerCount);
        QTrainIteration[] trainingReport = lloydMax.train(false);
//        saveQTrainLog(String.format("p%d_cb_%d_lloyd.csv", planeIndex, codebookSize), trainingReport);
        return new ScalarQuantizer(U16.Min, U16.Max, lloydMax.getCodebook());
    }
}