Geotools - Draw Features on WMS and OSM - gdal

Question

I am trying to overlay a shp file on wms layer using the example http://docs.geotools.org/latest/userguide/tutorial/raster/image.html.
I am continuously getting the error:
Exception in thread "main" java.lang.UnsupportedOperationException: Trying to get a reader from an unknown format.
at org.geotools.coverage.grid.io.UnknownFormat.getReader(UnknownFormat.java:62)
at com.qedrix.map.maplotr.Demo1.displayLayers(Demo1.java:121)
at com.qedrix.map.maplotr.Demo1.main(Demo1.java:229)
when the code tries to read the WMS image.
My code looks like this:
public class Demo1 {
private AbstractGridCoverage2DReader reader = null;
private StyleFactory sf = CommonFactoryFinder.getStyleFactory();
private FilterFactory2 ff = CommonFactoryFinder.getFilterFactory2();
/**
* This method examines the names of the sample dimensions in the provided
* coverage looking for "red...", "green..." and "blue..." (case insensitive
* match). If these names are not found it uses bands 1, 2, and 3 for the
* red, green and blue channels. It then sets up a raster symbolizer and
* returns this wrapped in a Style.
*
* #return a new Style object containing a raster symbolizer set up for RGB
* image
*/
private Style createRGBStyle() {
GridCoverage2D cov = null;
try {
cov = reader.read(null);
} catch (IOException giveUp) {
throw new RuntimeException(giveUp);
}
// We need at least three bands to create an RGB style
int numBands = cov.getNumSampleDimensions();
if (numBands < 3) {
return null;
}
// Get the names of the bands
String[] sampleDimensionNames = new String[numBands];
for (int i = 0; i < numBands; i++) {
GridSampleDimension dim = cov.getSampleDimension(i);
sampleDimensionNames[i] = dim.getDescription().toString();
}
final int RED = 0, GREEN = 1, BLUE = 2;
int[] channelNum = { -1, -1, -1 };
// We examine the band names looking for "red...", "green...",
// "blue...".
// Note that the channel numbers we record are indexed from 1, not 0.
for (int i = 0; i < numBands; i++) {
String name = sampleDimensionNames[i].toLowerCase();
if (name != null) {
if (name.matches("red.*")) {
channelNum[RED] = i + 1;
} else if (name.matches("green.*")) {
channelNum[GREEN] = i + 1;
} else if (name.matches("blue.*")) {
channelNum[BLUE] = i + 1;
}
}
}
// If we didn't find named bands "red...", "green...", "blue..."
// we fall back to using the first three bands in order
if (channelNum[RED] < 0 || channelNum[GREEN] < 0 || channelNum[BLUE] < 0) {
channelNum[RED] = 1;
channelNum[GREEN] = 2;
channelNum[BLUE] = 3;
}
// Now we create a RasterSymbolizer using the selected channels
SelectedChannelType[] sct = new SelectedChannelType[cov.getNumSampleDimensions()];
ContrastEnhancement ce = sf.contrastEnhancement(ff.literal(1.0), ContrastMethod.NORMALIZE);
for (int i = 0; i < 3; i++) {
sct[i] = sf.createSelectedChannelType(String.valueOf(channelNum[i]), ce);
}
RasterSymbolizer sym = sf.getDefaultRasterSymbolizer();
ChannelSelection sel = sf.channelSelection(sct[RED], sct[GREEN], sct[BLUE]);
sym.setChannelSelection(sel);
return SLD.wrapSymbolizers(sym);
}
public void displayLayers() {
File rasterFile = fetchWmsImage();
AbstractGridFormat format = GridFormatFinder.findFormat(rasterFile);
this.reader = format.getReader(rasterFile);
// Initially display the raster in greyscale using the
// data from the first image band
Style rasterStyle = createRGBStyle();
// Create a basic style with yellow lines and no fill
Style shpStyle = SLD.createPointStyle("point", Color.YELLOW, Color.GRAY, 0.0f, 1.5f);
MapContent map = new MapContent();
map.setTitle("ImageLab");
MapViewport vp = new MapViewport();
org.geotools.map.Layer rasterLayer = new GridReaderLayer(reader, rasterStyle);
map.addLayer(rasterLayer);
saveImage(map, "final.jpeg", 583);
}
public File fetchWmsImage() {
URL url = null;
try {
url = new URL("http://184.106.187.247:8080/geoserver/rg/wms?version=1.1.0");
} catch (MalformedURLException e) {
// will not happen
}
WebMapServer wms = null;
try {
wms = new WebMapServer(url);
WMSCapabilities capabilities = wms.getCapabilities();
Layer[] layers = WMSUtils.getNamedLayers(capabilities);
GetMapRequest request = wms.createGetMapRequest();
request.setFormat("image/png");
request.setDimensions("583", "420");
request.setTransparent(true);
request.setSRS("EPSG:900913");
request.setBBox("-13019428.542822,3922163.1648461,-13013051.407366,3929863.8567165");
request.setProperty("isBaseLayer", "false");
request.setProperty("opacity", ".2");
for (Layer layer : WMSUtils.getNamedLayers(capabilities)) {
if (layer.getName().equals("rg:parcels"))
request.addLayer(layer);
}
GetMapResponse response = (GetMapResponse) wms.issueRequest(request);
BufferedImage image = ImageIO.read(response.getInputStream());
File rasterFile = new File("C:\\Users\\samabhik\\Workspace\\MAP\\data\\out.png");
ImageIO.write(image, "png", rasterFile);
return rasterFile;
} catch (ServiceException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
}
return null;
}
public void saveImage(final MapContent map, final String file, final int imageWidth) {
GTRenderer renderer = new StreamingRenderer();
renderer.setMapContent(map);
Rectangle imageBounds = null;
ReferencedEnvelope mapBounds = null;
try {
mapBounds = map.getMaxBounds();
double heightToWidth = mapBounds.getSpan(1) / mapBounds.getSpan(0);
imageBounds = new Rectangle(0, 0, imageWidth, (int) Math.round(imageWidth * heightToWidth));
} catch (Exception e) {
// failed to access map layers
throw new RuntimeException(e);
}
BufferedImage image = new BufferedImage(imageBounds.width, imageBounds.height, BufferedImage.TYPE_INT_RGB);
Graphics2D gr = image.createGraphics();
gr.setPaint(Color.WHITE);
gr.fill(imageBounds);
try {
renderer.paint(gr, imageBounds, mapBounds);
File fileToSave = new File(file);
ImageIO.write(image, "jpeg", fileToSave);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
public static void main(String[] args) {
Demo1 demo = new Demo1();
demo.displayLayers();
}
}
My pom dependency looks like this:
<dependency>
<groupId>org.geotools</groupId>
<artifactId>gt-shapefile</artifactId>
<version>${geotools.version}</version>
</dependency>
<dependency>
<groupId>org.geotools</groupId>
<artifactId>gt-swing</artifactId>
<version>${geotools.version}</version>
</dependency>
<dependency>
<groupId>org.geotools</groupId>
<artifactId>gt-epsg-hsql</artifactId>
<version>${geotools.version}</version>
</dependency>
<dependency>
<groupId>org.geotools</groupId>
<artifactId>gt-geotiff</artifactId>
<version>${geotools.version}</version>
</dependency>
<dependency>
<groupId>org.geotools</groupId>
<artifactId>gt-image</artifactId>
<version>${geotools.version}</version>
</dependency>
<dependency>
<groupId>org.geotools</groupId>
<artifactId>gt-wms</artifactId>
<version>${geotools.version}</version>
</dependency>
<dependency>
<groupId>org.geotools</groupId>
<artifactId>gt-coverage</artifactId>
<version>${geotools.version}</version>
</dependency>
Somewhere I read that it could a GDAL issue. But I couldn't figure out how to resolve it. I am using eclipse on 64 JDK 1.6 and Win 7 amd64.
Please help, someone..
Just tested the image file using gdalinfo.exe found in the GDAL native libraries path. Here's the report:
Driver: PNG/Portable Network Graphics
Files: ..\..\Workspace\MAP\data\out2.png
Size is 583, 420
Coordinate System is `'
Image Structure Metadata:
INTERLEAVE=PIXEL
Corner Coordinates:
Upper Left ( 0.0, 0.0)
Lower Left ( 0.0, 420.0)
Upper Right ( 583.0, 0.0)
Lower Right ( 583.0, 420.0)
Center ( 291.5, 210.0)
Band 1 Block=583x1 Type=Byte, ColorInterp=Red
Mask Flags: PER_DATASET ALPHA
Band 2 Block=583x1 Type=Byte, ColorInterp=Green
Mask Flags: PER_DATASET ALPHA
Band 3 Block=583x1 Type=Byte, ColorInterp=Blue
Mask Flags: PER_DATASET ALPHA
Band 4 Block=583x1 Type=Byte, ColorInterp=Alpha
FURTHER UPDATES
I just tried and changed the out format for WMS from images/png to images/geotiff and this now works partially ( the final image that is generated by geotools is Black & White). Why this is happening? And why it didn't work with PNG?

Answer 1

Check that you have JAI and ImageIO avaialble. Either via maven dependency, or by installing them as Java Extensions as outlined in the Quickstart.
http://docs.geotools.org/latest/userguide/tutorial/quickstart/eclipse.html
Update:
I was able to catch up on the GeoTools IRC channel and confirm this is an environment issue. In class works for me fashion I was able to connect using the WMSLab tutorial example to the WMS in question and display results.
So lets check out "problem" environment::
System.out.println( GeoTools.getAboutInfo() );
Result::
GeoTools version 9-SNAPSHOT (built from ree5a6830d2c774ee9a4eb9e024d989c2a1bcdfe3)
Java version: 1.7.0_09
Operating system: Windows 7 6.1
GeoTools jars on classpath:
A couple ideas:
Check out the ImageLab to confirm JAI / ImageIO is availble?
This worked!
Save the image retrieved from the browser and try loading it using straight up Java
Example from WorldImageReader::
File input = ...
ImageInputStreamSpi inStreamSPI= ImageIOExt.getImageInputStreamSPI( input );
if (inStreamSPI == null) throw new IllegalStateException("Unsuppported");
Apparently this was not successful?
GeoTools has not gone through QA on Java 7 yet, downgrade to Java 6?
Recently a Java 7 build box has been volunteered. When GeoTools works in Java 7 the release notes and tutorials will be updated.
Especially on windows the implementation of PNG support is suspect.
The following code from the uDig project disables the native implementation allowing the pure Java implementation to have a crack at it::
if (Platform.getOS().equals(Platform.OS_WIN32)) {
try {
// PNG native support is not very good .. this turns it off
ImageUtilities.allowNativeCodec("png", ImageReaderSpi.class, false); //$NON-NLS-1$
} catch (Throwable t) {
// we should not die if JAI is missing; we have a warning for that...
System.out.println("Difficulty turnning windows native PNG support (which will result in scrambled images from WMS servers)"); //$NON-NLS-1$
t.printStackTrace();
}
}