/*
* Copyright (C) 2011-2012 Dr. John Lindsay <jlindsay@uoguelph.ca>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package plugins;
import java.awt.Color;
import java.util.Date;
import whitebox.geospatialfiles.WhiteboxRaster;
import whitebox.interfaces.WhiteboxPlugin;
import whitebox.interfaces.WhiteboxPluginHost;
/**
* This tool alters the cumulative distribution function (CDF) of a raster image to match, as closely as possible, the CDF of a uniform distribution.
* @author Dr. John Lindsay email: jlindsay@uoguelph.ca
*/
public class HistogramEqualization implements WhiteboxPlugin {
private WhiteboxPluginHost myHost = null;
private String[] args;
/**
* Used to retrieve the plugin tool's name. This is a short, unique name containing no spaces.
* @return String containing plugin name.
*/
@Override
public String getName() {
return "HistogramEqualization";
}
/**
* Used to retrieve the plugin tool's descriptive name. This can be a longer name (containing spaces) and is used in the interface to list the tool.
* @return String containing the plugin descriptive name.
*/
@Override
public String getDescriptiveName() {
return "Histogram Equalization";
}
/**
* Used to retrieve a short description of what the plugin tool does.
* @return String containing the plugin's description.
*/
@Override
public String getToolDescription() {
return "Performs a histogram equalization contrast enhancment on an image.";
}
/**
* Used to identify which toolboxes this plugin tool should be listed in.
* @return Array of Strings.
*/
@Override
public String[] getToolbox() {
String[] ret = { "ImageEnhancement" };
return ret;
}
/**
* Sets the WhiteboxPluginHost to which the plugin tool is tied. This is the class
* that the plugin will send all feedback messages, progress updates, and return objects.
* @param host The WhiteboxPluginHost that called the plugin tool.
*/
@Override
public void setPluginHost(WhiteboxPluginHost host) {
myHost = host;
}
/**
* Used to communicate feedback pop-up messages between a plugin tool and the main Whitebox user-interface.
* @param feedback String containing the text to display.
*/
private void showFeedback(String message) {
if (myHost != null) {
myHost.showFeedback(message);
} else {
System.out.println(message);
}
}
/**
* Used to communicate a return object from a plugin tool to the main Whitebox user-interface.
* @return Object, such as an output WhiteboxRaster.
*/
private void returnData(Object ret) {
if (myHost != null) {
myHost.returnData(ret);
}
}
private int previousProgress = 0;
private String previousProgressLabel = "";
/**
* Used to communicate a progress update between a plugin tool and the main Whitebox user interface.
* @param progressLabel A String to use for the progress label.
* @param progress Float containing the progress value (between 0 and 100).
*/
private void updateProgress(String progressLabel, int progress) {
if (myHost != null && ((progress != previousProgress) ||
(!progressLabel.equals(previousProgressLabel)))) {
myHost.updateProgress(progressLabel, progress);
}
previousProgress = progress;
previousProgressLabel = progressLabel;
}
/**
* Used to communicate a progress update between a plugin tool and the main Whitebox user interface.
* @param progress Float containing the progress value (between 0 and 100).
*/
private void updateProgress(int progress) {
if (myHost != null && progress != previousProgress) {
myHost.updateProgress(progress);
}
previousProgress = progress;
}
/**
* Sets the arguments (parameters) used by the plugin.
* @param args An array of string arguments.
*/
@Override
public void setArgs(String[] args) {
this.args = args.clone();
}
private boolean cancelOp = false;
/**
* Used to communicate a cancel operation from the Whitebox GUI.
* @param cancel Set to true if the plugin should be canceled.
*/
@Override
public void setCancelOp(boolean cancel) {
cancelOp = cancel;
}
private void cancelOperation() {
showFeedback("Operation cancelled.");
updateProgress("Progress: ", 0);
}
private boolean amIActive = false;
/**
* Used by the Whitebox GUI to tell if this plugin is still running.
* @return a boolean describing whether or not the plugin is actively being used.
*/
@Override
public boolean isActive() {
return amIActive;
}
/**
* Used to execute this plugin tool.
*/
@Override
public void run() {
amIActive = true;
String outputHeader = null;
String inputFilesString = null;
String outputFileSuffix = "_HistoEqual";
WhiteboxRaster image = null;
WhiteboxRaster output = null;
int row, col;
int rows = 0;
int cols = 0;
double z;
float progress = 0;
long numCells = 0;
int i = 0;
String[] imageFiles;
int numImages = 0;
double noData = -32768;
int numBins = 1024;
if (args.length <= 0) {
showFeedback("Plugin parameters have not been set.");
return;
}
inputFilesString = args[0];
outputFileSuffix = args[1];
numBins = Integer.parseInt(args[2]);
// check to see that the inputHeader and outputHeader are not null.
if ((inputFilesString == null) || (outputFileSuffix == null)) {
showFeedback("One or more of the input parameters have not been set properly.");
return;
}
imageFiles = inputFilesString.split(";");
numImages = imageFiles.length;
try {
for (i = 0; i < numImages; i++) {
image = new WhiteboxRaster(imageFiles[i], "r");
noData = image.getNoDataValue();
rows = image.getNumberRows();
cols = image.getNumberColumns();
outputHeader = imageFiles[i].replace(".dep", outputFileSuffix + ".dep");
output = new WhiteboxRaster(outputHeader, "rw", imageFiles[i],
WhiteboxRaster.DataType.INTEGER, noData);
output.setPreferredPalette(image.getPreferredPalette());
double minValue = image.getMinimumValue();
double maxValue = image.getMaximumValue();
double binSize = (maxValue - minValue) / numBins;
long[] histogram = new long[numBins];
int binNum;
int numBinsLessOne = numBins - 1;
double[] data;
if (image.getDataScale() != WhiteboxRaster.DataScale.RGB) {
updateProgress("Loop 1 of 2:", 0);
for (row = 0; row < rows; row++) {
data = image.getRowValues(row);
for (col = 0; col < cols; col++) {
if (data[col] != noData) {
numCells++;
binNum = (int) ((data[col] - minValue) / binSize);
if (binNum > numBinsLessOne) {
binNum = numBinsLessOne;
}
histogram[binNum]++;
}
}
if (cancelOp) {
cancelOperation();
return;
}
progress = (float) (100f * row / (rows - 1));
updateProgress("Loop 1 of 2:", (int) progress);
}
double[] cdf = new double[numBins];
cdf[0] = histogram[0];
for (int j = 1; j < numBins; j++) {
cdf[j] = cdf[j - 1] + histogram[j];
}
histogram = null;
updateProgress("Loop 2 of 2:", 0);
for (row = 0; row < rows; row++) {
data = image.getRowValues(row);
for (col = 0; col < cols; col++) {
if (data[col] != noData) {
binNum = (int) ((data[col] - minValue) / binSize);
if (binNum > numBinsLessOne) {
binNum = numBinsLessOne;
}
z = Math.round((cdf[binNum] - cdf[0]) / (numCells - cdf[0]) * numBinsLessOne);
output.setValue(row, col, z);
}
}
if (cancelOp) {
cancelOperation();
return;
}
progress = (float) (100f * row / (rows - 1));
updateProgress("Loop 2 of 2:", (int) progress);
}
} else {
output = new WhiteboxRaster(outputHeader, "rw", imageFiles[i],
WhiteboxRaster.DataType.FLOAT, noData);
output.setPreferredPalette(image.getPreferredPalette());
output.setDataScale(WhiteboxRaster.DataScale.RGB);
// convert the rgb to hsv and calculate the histogram for the 'v'
double h, s, v;
int a, r, g, b;
minValue = 99999999;
maxValue = -99999999;
float[] hsbvals = new float[3];
float[] rgbvals = new float[3];
updateProgress("Loop 1 of 3:", 0);
for (row = 0; row < rows; row++) {
data = image.getRowValues(row);
for (col = 0; col < cols; col++) {
if (data[col] != noData) {
r = (int) data[col] & 0xFF;
g = ((int) data[col] >> 8) & 0xFF;
b = ((int) data[col] >> 16) & 0xFF;
Color.RGBtoHSB(r, g, b, hsbvals);
v = hsbvals[2];
if (v < minValue) {
minValue = v;
}
if (v > maxValue) {
maxValue = v;
}
}
}
if (cancelOp) {
cancelOperation();
return;
}
progress = (float) (100f * row / (rows - 1));
updateProgress("Loop 1 of 3:", (int) progress);
}
binSize = (maxValue - minValue) / numBins;
histogram = new long[numBins];
numBinsLessOne = numBins - 1;
updateProgress("Loop 2 of 3:", 0);
for (row = 0; row < rows; row++) {
data = image.getRowValues(row);
for (col = 0; col < cols; col++) {
if (data[col] != noData) {
r = (int) data[col] & 0xFF;
g = ((int) data[col] >> 8) & 0xFF;
b = ((int) data[col] >> 16) & 0xFF;
Color.RGBtoHSB(r, g, b, hsbvals);
v = hsbvals[2];
numCells++;
binNum = (int) ((v - minValue) / binSize);
if (binNum > numBinsLessOne) {
binNum = numBinsLessOne;
}
histogram[binNum]++;
}
}
if (cancelOp) {
cancelOperation();
return;
}
progress = (float) (100f * row / (rows - 1));
updateProgress("Loop 2 of 3:", (int) progress);
}
double[] cdf = new double[numBins];
cdf[0] = histogram[0];
for (int j = 1; j < numBins; j++) {
cdf[j] = cdf[j - 1] + histogram[j];
}
histogram = null;
updateProgress("Loop 3 of 3:", 0);
float val = 0;
int rgb = 0;
for (row = 0; row < rows; row++) {
data = image.getRowValues(row);
for (col = 0; col < cols; col++) {
if (data[col] != noData) {
z = data[col];
r = (int) data[col] & 0xFF;
g = ((int) data[col] >> 8) & 0xFF;
b = ((int) data[col] >> 16) & 0xFF;
a = ((int) data[col] >> 24) & 0xFF;
hsbvals = Color.RGBtoHSB(r, g, b, null);
v = hsbvals[2];
binNum = (int) ((v - minValue) / binSize);
if (binNum > numBinsLessOne) {
binNum = numBinsLessOne;
}
val = (float) ((cdf[binNum] - cdf[0]) / (numCells - cdf[0]));
rgb = Color.HSBtoRGB(hsbvals[0], hsbvals[1], val);
r = (rgb >> 16) & 0xFF;
g = (rgb >> 8) & 0xFF;
b = rgb & 0xFF;
z = (double) ((a << 24) | (b << 16) | (g << 8) | r);
output.setValue(row, col, z);
}
}
if (cancelOp) {
cancelOperation();
return;
}
progress = (float) (100f * row / (rows - 1));
updateProgress("Loop 3 of 3:", (int) progress);
}
}
output.addMetadataEntry("Created by the "
+ getDescriptiveName() + " tool.");
output.addMetadataEntry("Created on " + new Date());
image.close();
output.close();
// returning a header file string displays the image.
returnData(outputHeader);
}
} catch (OutOfMemoryError oe) {
myHost.showFeedback("An out-of-memory error has occurred during operation.");
} catch (Exception e) {
myHost.showFeedback("An error has occurred during operation. See log file for details.");
myHost.logException("Error in " + getDescriptiveName(), e);
} finally {
updateProgress("Progress: ", 0);
// tells the main application that this process is completed.
amIActive = false;
myHost.pluginComplete();
}
}
}