All,
Please find appended a program which is a modification to an example program
from the tutorial
on VisAD. Essential it draws iso-contours for temperature values and fills
these contours. Most
experts will find it a trivial program.
My question is this. The image generated is not filling up the screen i.e.,
there seems to be a padded
area drawn around the actual image. How can I eliminate this "border" so that
the required image fills
up the entire space of (NumXPixels * NumYPixels)? Appreciate your help.
sincerely,
Ramesh Mantri
// ===========================================================================
import visad.*;
import visad.java2d.DisplayImplJ2D;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.io.*;
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
public class Image2D {
private RealType longitude, latitude;
private RealType temperature;
private RealTupleType domain_tuple;
private FunctionType func_domain_range;
private Set domain_set;
private FlatField vals_ff;
private DataReferenceImpl data_ref;
private DisplayImpl display;
private ScalarMap latMap, lonMap;
private ScalarMap tempIsoMap, tempRGBMap;
public Image2D(float[] data, int NCOLS, int NROWS) throws Exception {
latitude = RealType.getRealType("latitude");
longitude = RealType.getRealType("longitude");
domain_tuple = new RealTupleType(latitude, longitude);
temperature = RealType.getRealType("temperature");
func_domain_range = new FunctionType( domain_tuple, temperature);
domain_set = new Linear2DSet(domain_tuple, 1,NROWS,NROWS, 1,NCOLS,NCOLS);
float[][] set_samples = domain_set.getSamples(true);
float[][] flat_samples = new float[1][NCOLS * NROWS];
for (int dataIndex=0; dataIndex < data.length; dataIndex++) {
int dataCol = (dataIndex % NCOLS);
int dataRow = (dataIndex / NCOLS);
int sampleIndex = ((dataCol * NROWS) + dataRow);
flat_samples[0][sampleIndex] = data[dataIndex];
}
vals_ff = new FlatField( func_domain_range, domain_set);
vals_ff.setSamples( flat_samples , false );
int NumXPixels = 450;
int NumYPixels = 450;
if (NROWS != NCOLS) {
boolean Xmax = (NCOLS > NROWS);
if (Xmax) {
NumYPixels = (int) ((NumXPixels * NROWS) / NCOLS);
} else {
NumXPixels = (int) ((NumYPixels * NCOLS) / NROWS);
}
display = new DisplayImplJ2D("display1", NumXPixels, NumYPixels);
latMap = new ScalarMap( latitude, Display.YAxis );
lonMap = new ScalarMap( longitude, Display.XAxis );
tempIsoMap = new ScalarMap( temperature, Display.IsoContour );
tempRGBMap = new ScalarMap( temperature, Display.RGB );
display.addMap( latMap );
display.addMap( lonMap );
display.addMap( tempIsoMap );
display.addMap( tempRGBMap );
ContourControl isoControl = (ContourControl) tempIsoMap.getControl();
float[] levels = {295.0f, 305.0f, 500.0f};
isoControl.setLevels(levels, 294.0f, false);
isoControl.setContourFill(true);
data_ref = new DataReferenceImpl("data_ref");
data_ref.setData( vals_ff );
display.addReference( data_ref );
double ar = ((double) NumYPixels) / ((double) NumXPixels);
ProjectionControl pc = display.getProjectionControl();
pc.setAspect(new double[] {1.0, ar});
}
public void writeToFile() throws IOException {
BufferedImage image = display.getImage(true);
File file = new File("iso_contour_image.png");
ImageIO.write(image, "PNG", file);
}
public static void main(String[] args) {
try {
float[] data = {
318.0f, 312.0f, 297.0f, 299.0f, 302.0f,
315.0f, 311.0f, 296.0f, 297.0f, 299.0f,
306.0f, 298.0f, 297.0f, 294.0f, 294.0f,
297.0f, 296.0f, 294.0f, 291.0f, 294.0f,
297.0f, 291.0f, 293.0f, 287.0f, 285.0f,
297.0f, 296.0f, 296.0f, 291.0f, 291.0f
};
Image2D imgObj = new Image2D(data, 5, 6);
imgObj.writeToFile();
System.out.println("Image written to file");
} catch (Exception e) {
e.printStackTrace();
}
}
}
// ===========================================================================
