    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.imaging.formats.tiff;
    018
    019/**
    020 * Collects and stores a set of simple statistics from the input raster.
    021 */
    022public class TiffRasterStatistics {
    023
    024    private final int nSample;
    025    private final int nNull;
    026    private final float minValue;
    027    private final float maxValue;
    028    private final float meanValue;
    029    private final float excludedValue;
    030
    031    /**
    032     * Constructs an instance of this class, tabulating results from the input
    033     * raster data.
    034     *
    035     * @param raster the input data
    036     * @param excludedValue an optional value to ignore; use Float&#46;NaN if no
    037     * value is to be ignored.
    038     */
    039    TiffRasterStatistics(final TiffRasterData raster, final float excludedValue) {
    040        this.excludedValue = excludedValue;
    041        float vMin = Float.POSITIVE_INFINITY;
    042        float vMax = Float.NEGATIVE_INFINITY;
    043        double vSum = 0;
    044        int nS = 0;
    045        int nN = 0;
    046        final float[] data = raster.getData();
    047        for (final float test : data) {
    048            if (Float.isNaN(test)) {
    049                nN++;
    050                continue;
    051            }
    052            if (test == excludedValue) {
    053                continue;
    054            }
    055
    056            nS++;
    057            vSum += test;
    058            if (test < vMin) {
    059                vMin = test;
    060            }
    061            if (test > vMax) {
    062                vMax = test;
    063            }
    064        }
    065
    066        minValue = vMin;
    067        maxValue = vMax;
    068        nSample = nS;
    069        nNull = nN;
    070        if (nSample == 0) {
    071            meanValue = 0;
    072        } else {
    073            meanValue = (float) (vSum / nSample);
    074        }
    075    }
    076
    077    /**
    078     * Get the count of the number of non-null and non-excluded samples in the
    079     * collection.
    080     *
    081     * @return the a positive number, potentially zero
    082     */
    083    public int getCountOfSamples() {
    084        return nSample;
    085    }
    086
    087    /**
    088     * Get the count of the number of null samples in the collection.
    089     *
    090     * @return the a positive number, potentially zero
    091     */
    092    public int getCountOfNulls() {
    093        return nNull;
    094    }
    095
    096    /**
    097     * Get the minimum value found in the source data
    098     *
    099     * @return the minimum value found in the source data
    100     */
    101    public float getMinValue() {
    102        return minValue;
    103    }
    104
    105    /**
    106     * Get the maximum value found in the source data
    107     *
    108     * @return the maximum value found in the source data
    109     */
    110    public float getMaxValue() {
    111        return maxValue;
    112    }
    113
    114    /**
    115     * Get the mean value for all sample values in the raster. Null-data values
    116     * and excluded values are not considered.
    117     *
    118     * @return the mean value of the samples
    119     */
    120    public float getMeanValue() {
    121        return meanValue;
    122    }
    123
    124    /**
    125     * Indicates if a sample value was set to be deliberately excluded from the
    126     * statistics.
    127     *
    128     * @return true if a value was set for exclusion; otherwise, false
    129     */
    130    public boolean isAnExcludedValueSet() {
    131        return !Float.isNaN(excludedValue);
    132    }
    133
    134    /**
    135     * Get the value that was set for exclusion, or a Float&#46;NaN if not was
    136     * set.
    137     *
    138     * @return the excluded value (if any).
    139     */
    140    public float getExcludedValue() {
    141        return excludedValue;
    142    }
    143}