kinow commented on a change in pull request #72: URL: https://github.com/apache/commons-imaging/pull/72#discussion_r422592479
########## File path: src/main/java/org/apache/commons/imaging/formats/tiff/TiffRasterStatistics.java ########## @@ -0,0 +1,144 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.commons.imaging.formats.tiff; + +/** + * Collects and stores a set of simple statistics from the input raster. + */ +public class TiffRasterStatistics { + + private final int nSample; + private final int nNull; + private final float minValue; + private final float maxValue; + private final float meanValue; + private final float excludedValue; + + /** + * Constructs an instance of this class, tabulating results from the input + * raster data. + * + * @param raster the input data + * @param excludedValue an optional value to ignore; use Float.NaN if no + * value is to be ignored. + */ + TiffRasterStatistics(TiffRasterData raster, float excludedValue) { + this.excludedValue = excludedValue; + float vMin = Float.POSITIVE_INFINITY; + float vMax = Float.NEGATIVE_INFINITY; + double vSum = 0; + int nS = 0; + int nN = 0; + float[] data = raster.getData(); + for (int i = 0; i < data.length; i++) { + float test = data[i]; + if (Float.isNaN(test)) { + nN++; + continue; + } + if (test == excludedValue) { + continue; + } + + nS++; + vSum += test; + if (test < vMin) { + vMin = test; + } + if (test > vMax) { + vMax = test; + } + } + + minValue = vMin; + maxValue = vMax; + nSample = nS; + nNull = nN; + if (nSample == 0) { + meanValue = 0; + } else { + meanValue = (float) (vSum / nSample); + } + } + + /** + * Get the count of the number of non-null and non-excluded samples in the + * collection. + * + * @return the a positive number, potentially zero + */ + public int getCountOfSamples() { + return nSample; + } + + /** + * Get the count of the number of null samples in the collection. + * + * @return the a positive number, potentially zero + */ + public int getCountOfNulls() { + return nNull; + } + + /** + * Get the minimum value found in the source data + * + * @return the minimum value found in the source data + */ + public float getMinValue() { + return minValue; + } + + /** + * Get the maximum value found in the source data + * + * @return the maximum value found in the source data + */ + public float getMaxValue() { + return maxValue; + } + + /** + * Get the mean value for all sample values in the raster. Null-data values + * and excluded values are not considered. + * + * @return the meanValuethe mean value of the samples Review comment: "return the mean value of the samples" ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
