Re: [Fwd: multi band tiff from netCDF]

Hi Norman:

Thanks for the code. We looked at using JAI to write TIFF, but failed to get it working ("JAI documentation is a bit sparse"). Is the code the complete way to do that? Are there any problems with it that you know of? It doesnt appear that youve added the geotiff tags, is that correct? Any advice you can give us on using or not using JAI?

thanks again!




Norman Barker wrote:

Thanks for the reply, I will top post (apologies) since the file is long.

I wrote some test code before I integrated into my app, and using netcdf-java 
and
JAI the following creates a multiband tif file. (there are some redundant 
variables in
there, apologies again).  JAI documentation is a bit sparse, so hope this helps.

Norman

        public static void main(String[] args) {
                String testNC = "/temp/test.nc";
                String outGTif = "/temp/out.tif";
                String gridName = "ta";
                try {
                        NetcdfDataset ncDataset = 
NetcdfDataset.openDataset(testNC);
                        
                        GridDataset gSet = new GridDataset(ncDataset);
                        GeoGrid grid = gSet.findGridByName(gridName);
           GridCoordSys gcs = grid.getCoordinateSystem();
                        
                    //latlon coord does not need to be scaled
                    double scaler = (gcs.isLatLon()) ? 1.0 : 1000.0;

                    CoordinateAxis1D xaxis = (CoordinateAxis1D) 
gcs.getXHorizAxis();
                    CoordinateAxis1D yaxis = (CoordinateAxis1D) 
gcs.getYHorizAxis();
                    double xStart = xaxis.getCoordValue(0) * scaler;
                    double yStart = yaxis.getCoordValue(0) * scaler;
                        double xEnd = 
xaxis.getCoordValue(grid.getXDimension().getLength()-1) * scaler;
                        double yEnd = 
yaxis.getCoordValue(grid.getYDimension().getLength()-1) * scaler;
                        double xInc = (xEnd - xStart)/xaxis.getElementSize();
                        double yInc = (yEnd - yStart)/yaxis.getElementSize();
                        
                        
                        
                        List list = ncDataset.getCoordinateAxes();
                        Iterator itr = list.iterator();

                        while (itr.hasNext()) {
                                CoordinateAxis1D dim = (CoordinateAxis1D) 
itr.next();
                                String dimName = dim.getName();

                                if (dimName.equals(IngestFile.DIM_NAME)) {
                                        int nBands = (int) dim.getSize();
                                        if (dim.isUnlimited()) {
                                                // we can't do anything, log
                                                return;
                                        }
                                        
                                        int width = 
grid.getXDimension().getLength();
                                        int height = 
grid.getYDimension().getLength();
                
                                        ParameterBlockJAI pbjai = new 
ParameterBlockJAI("bandmerge");
                                        
                                        for (int i = 0; i < nBands; i++)
                                        {
                                                Array arr = 
grid.readDataSlice(-1, i, -1, -1);
                                                float[] data = (float[]) 
arr.getStorage();
                                                DataBufferFloat dbuffer = new 
DataBufferFloat(data, width*height);
                                                
                                                // create a float data sample 
model
                                                SampleModel sampleModel = 
RasterFactory.createBandedSampleModel(DataBuffer.TYPE_FLOAT, width, height, 1);
                                                
                                                // create a compatible colour 
model
                                                ColorModel colorModel = 
PlanarImage.createColorModel(sampleModel);
                                                
                                                // create a writable raster
                                                Raster raster = 
RasterFactory.createWritableRaster(sampleModel, dbuffer, null);
                                                
                                                // create a tiled image using 
the float sample model
                                                TiledImage tiledImage = new 
TiledImage(0, 0, width, height, 0, 0, sampleModel, colorModel);
                                                
                                                // set the data of the tiled 
image to be the raster
                                                tiledImage.setData(raster);
                                                
                                                pbjai.setSource(tiledImage, i);
                                        }
                                        // save the image on a file
                                        PlanarImage result = 
JAI.create("bandmerge", pbjai, null);
                                        JAI.create("filestore", result, outGTif, 
"TIFF");
                                        break;
                                }
                        }
                } catch (Exception e) {
                        e.printStackTrace();
                }

        }

-----Original Message-----
From: Yuan Ho [mailto:yuanho@xxxxxxxxxxxxxxxx]
Sent: Monday, April 18, 2005 5:27 PM
To: Norman Barker
Cc: netcdf-java@xxxxxxxxxxxxxxxx; support-netcdf-java@xxxxxxxxxxxxxxxx
Subject: Re: [Fwd: multi band tiff from netCDF]


John Caron wrote:

can you answer this?
cc to netcdf-java@xxxxxxxxxxxxxxxx and support-netcdf-java@xxxxxxxxxxxxxxxx

-------- Original Message --------
Subject:     multi band tiff from netCDF
Date:     Mon, 18 Apr 2005 16:01:21 +0100
From:     Norman Barker <nbarker@xxxxxxxxx>
Organization:     UCAR/Unidata
To:     <netcdf-java@xxxxxxxxxxxxxxxx>



Hi,

I am using the java classes to convert a netcdf file for one time instance, with 27 levels in Z (atmospheric pressure levels).

I have created a loop with variable i, and attempting to write a band in the tif file for each iteration. What seems to happen is the first band gets written ok, but then after that
the page number gets messed up?

Array data = grid.readDataSlice(0, i, -1, -1);
writer.writeGrid(grid, data, false, xStart, yStart, xInc, yInc, i);

Has anyone got any pseudo code for writing multiband tif files from netCDF?

Many thanks,

Norman Barker

Norman,
The code was not designed for multiband tiff files. We originally believed that multipage was better to store multi variables and/or multi vertical levels. We just realized that multiband was probably better embraced because of the existing tiff readers and the concept of tiff community. This will be my next task to change the software to use multiband to store tiff files, it will be released sometime in the Summer.

Yuan