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.NaN if no
037     * value is to be ignored.
038     */
039    TiffRasterStatistics(TiffRasterData raster, 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        float[] data = raster.getData();
047        for (int i = 0; i < data.length; i++) {
048            float test = data[i];
049            if (Float.isNaN(test)) {
050                nN++;
051                continue;
052            }
053            if (test == excludedValue) {
054                continue;
055            }
056
057            nS++;
058            vSum += test;
059            if (test < vMin) {
060                vMin = test;
061            }
062            if (test > vMax) {
063                vMax = test;
064            }
065        }
066
067        minValue = vMin;
068        maxValue = vMax;
069        nSample = nS;
070        nNull = nN;
071        if (nSample == 0) {
072            meanValue = 0;
073        } else {
074            meanValue = (float) (vSum / nSample);
075        }
076    }
077
078    /**
079     * Get the count of the number of non-null and non-excluded samples in the
080     * collection.
081     *
082     * @return the a positive number, potentially zero
083     */
084    public int getCountOfSamples() {
085        return nSample;
086    }
087
088    /**
089     * Get the count of the number of null samples in the collection.
090     *
091     * @return the a positive number, potentially zero
092     */
093    public int getCountOfNulls() {
094        return nNull;
095    }
096
097    /**
098     * Get the minimum value found in the source data
099     *
100     * @return the minimum value found in the source data
101     */
102    public float getMinValue() {
103        return minValue;
104    }
105
106    /**
107     * Get the maximum value found in the source data
108     *
109     * @return the maximum value found in the source data
110     */
111    public float getMaxValue() {
112        return maxValue;
113    }
114
115    /**
116     * Get the mean value for all sample values in the raster. Null-data values
117     * and excluded values are not considered.
118     *
119     * @return the mean value of the samples
120     */
121    public float getMeanValue() {
122        return meanValue;
123    }
124
125    /**
126     * Indicates if a sample value was set to be deliberately excluded from the
127     * statistics.
128     *
129     * @return true if a value was set for exclusion; otherwise, false
130     */
131    public boolean isAnExcludedValueSet() {
132        return !Float.isNaN(excludedValue);
133    }
134
135    /**
136     * Get the value that was set for exclusion, or a Float&#46;NaN if not was
137     * set.
138     *
139     * @return the excluded value (if any).
140     */
141    public float getExcludedValue() {
142        return excludedValue;
143    }
144}