Hello, It looks like you are using the coordinates from the coverage envelope (world coordinates) directly with the Raster.getPixels method. However, the latter method expects image coordinates. You can retrieve the bounding image coordinates with the RenderedImage functions getMinX(), getMinY(), getWidth() and getHeight().
Also, it is generally better practice to use an image iterator to retrieve values rather than loading the whole image into memory - that way your code will still work with large images. GeoTools automagically includes the JAI and JAITools libraries, so you could use the JAI RectIter class or the slightly easier to use JAITools SimpleIterator class. Here are the links to the javadocs if you want to try that: http://docs.oracle.com/cd/E17802_01/products/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/iterator/RectIter.html http://jaitools.org/docs/jaitools/stable/apidocs/org/jaitools/imageutils/SimpleIterator.html Michael On 1 June 2012 10:51, agawrons <[email protected]> wrote: > I'm new to geomatics and GeoTools so this might be a silly question, but I'm > really stuck. I want to extract pixel data from a geoTiff image as a double > array but no matter what I try, all I get are zeros. > > Here is my code: > > File file = new File("./input/ASAR_04232010.tif"); > > AbstractGridFormat format = GridFormatFinder.findFormat(file); > AbstractGridCoverage2DReader reader = format.getReader(file); > > GridCoverage2D coverage = reader.read(null); > > RenderedImage rendImage = coverage.getRenderedImage(); > Raster raster = rendImage.getData(); > Envelope2D dim = coverage.getEnvelope2D(); > double[] array = new double[100]; > array = raster.getPixels((int)dim.x + 1, (int)dim.y + 1, 100, 0, array); > > for(double num : array){ > System.out.println(num + ""); > } > > I tried a different file and got the same result. Unfortunately the files > are too large to attach. > > Thanks in advance! > Alex > > -- > View this message in context: > http://osgeo-org.1560.n6.nabble.com/Retrieving-Pixel-Data-tp4978427.html > Sent from the geotools-gt2-users mailing list archive at Nabble.com. > > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. Discussions > will include endpoint security, mobile security and the latest in malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > GeoTools-GT2-Users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ GeoTools-GT2-Users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users
