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https://issues.apache.org/jira/browse/IMAGING-251?focusedWorklogId=432495&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-432495
]
ASF GitHub Bot logged work on IMAGING-251:
------------------------------------------
Author: ASF GitHub Bot
Created on: 10/May/20 06:10
Start Date: 10/May/20 06:10
Worklog Time Spent: 10m
Work Description: 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"
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Issue Time Tracking
-------------------
Worklog Id: (was: 432495)
Time Spent: 9h 50m (was: 9h 40m)
> Support TIFF standard floating point data
> -----------------------------------------
>
> Key: IMAGING-251
> URL: https://issues.apache.org/jira/browse/IMAGING-251
> Project: Commons Imaging
> Issue Type: New Feature
> Components: Format: TIFF
> Affects Versions: 1.x
> Reporter: Gary Lucas
> Priority: Major
> Fix For: 1.x
>
> Attachments: ArizonaHillshade.jpg, Imaging252_USGS_n38w077.jpg
>
> Time Spent: 9h 50m
> Remaining Estimate: 0h
>
> Commons Imaging does not support the floating-point format included in the
> TIFF specification. There are prominent data sources that issue products in
> this format. The ability to support this information would open up new
> application areas for Commons Imaging.
> TIFF is often used as a mechanism for distributing data from geophysical
> applications in the form of GeoTIFF files. Some of this is not imagery, but
> data. For example, the US Geological Survey is currently releasing
> high-resolution elevation data grids for the 3DEP program under the name
> Cloud-Optimized GeoTIFF (COG). It is a substantial data set with significant
> potential commercial and academic applications.
> To access this data means modifying the TIFF DataReaderStrips and
> DataReaderTile classes to recognize floating point data (which is typically
> indicated using TIFF tag #339, SampleFormat). Also, returning the data in the
> form of a BufferedImage makes no sense at all, so the API on the
> TiffImageParser and supporting classes would need additional methods to
> return arrays of floats. The good news here is that that requirement would
> mean adding new methods to the classes rather than making significant changes
> to existing classes. So the probability of unintended consequences or new
> bugs in existing code would be minimized.
> Specification details for floating-point are given in the main TIFF-6
> documentations and Adobe Photoshop TIFF Technical Note 3.
>
> I am willing to volunteer to make these changes provided that there is
> interest and a high probability that my contributions would be evaluated and,
> if suitable, integrated into the Commons Imaging code base.
> Thank you for your attention in this matter.
>
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