Utils.java

package compression.utilities;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;

public class Utils {

    public static double calculatePsnr(final double mse, final int signalMax) {
        double psnr = 10.0 * Math.log10((Math.pow(signalMax, 2) / mse));
        return psnr;
    }

    public static byte[] readFileBytes(final String path) throws FileNotFoundException {
        FileInputStream fileStream = new FileInputStream(path);
        try {
            return fileStream.readAllBytes();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return new byte[0];
    }

    public static <T> boolean arrayContains(final T[] array, final T element) {
        for (int i = 0; i < array.length; i++) {
            if (array[i].equals(element))
                return true;
        }
        return false;
    }

    public static double arrayListMax(final ArrayList<Double> array) {
        double max = Double.MIN_VALUE;
        for (final double val : array) {
            if (val > max) {
                max = val;
            }
        }
        return max;
    }

    public static boolean arrayContainsToIndex(final int[] array, final int toIndex, final int element) {
        for (int i = 0; i < toIndex; i++) {
            if (array[i] == element)
                return true;
        }
        return false;
    }

    public static int[] convertU16BytesToInt(final byte[] bytes) {
        assert (bytes.length % 2 == 0);
        int[] values = new int[bytes.length / 2];

        int index = 0;
        for (int i = 0; i < bytes.length; i += 2) {
            final int value = (int) (((bytes[i] & 0xff) << 8) | (bytes[i + 1] & 0xff));
            if (value > 0) {
                values[index++] = value;
                continue;
            }
            values[index++] = value;
        }
        return values;
    }

    public static double arrayListSum(final ArrayList<Double> array) {
        double sum = 0.0;
        for (final double val : array) {
            sum += val;
        }
        return sum;
    }
}