I am using hadoop to write some sample code which takes every image and blurs it using a blurring filter.
I was able to convert all my input images into a sequence file, and I've written the following hadoop code to perform the blurring operation. (The input sequencefile key-value pairs are Text (filename of the image), BytesWritable (image contents) for each record). 've used the TAR to sequence file creator available here: http://stuartsierra.com/2008/04/24/a-million-little-files But for some reason, I cannot get it working. I've pasted the code here (not including the imports), let me know what I'm doing wrong (I'm new to Hadoop btw). import com.jhlabs.image.BoxBlurFilter; //Mapper Class public class BlurMapper extends MapReduceBase implements Mapper<Text,BytesWritable,Text,BytesWritable> { public void map(Text key, BytesWritable file, OutputCollector<Text, BytesWritable> output, Reporter reporter) throws IOException { //Read Current Image from File. BufferedImage img = ImageIO.read(new ByteArrayInputStream (file.getBytes())); BufferedImage dest = null; //Apply Blur on Filter Operation - External JAR BoxBlurFilter BlurOp = new BoxBlurFilter(10,10,2); BlurOp.filter(img, dest); ByteArrayOutputStream outputbytes = new ByteArrayOutputStream(); ImageIO.write(dest, "jpeg", outputbytes); BytesWritable outfile = new BytesWritable(outputbytes.toByteArray()); output.collect(key, outfile); } } //MAIN CLASS public class BlurVideoHadoop { public static void main(String[] args) { if(args.length!=2) { System.err.println("Usage: blurvideo input output"); System.exit(-1); } JobClient client = new JobClient(); JobConf conf = new JobConf(BlurVideoHadoop.class); conf.setOutputKeyClass(Text.class); conf.setOutputValueClass(BytesWritable.class); SequenceFileInputFormat.addInputPath(conf, new Path(args[0])); SequenceFileOutputFormat.setOutputPath(conf, new Path(args[1])); conf.setMapperClass(BlurMapper.class); conf.setReducerClass(org.apache.hadoop.mapred.lib.IdentityReducer.class); client.setConf(conf); try { JobClient.runJob(conf); } catch (Exception e) { e.printStackTrace(); } } Thanks, Regards, Suhail Rehman MS by Research in Computer Science International Institute of Information Technology - Hyderabad reh...@research.iiit.ac.in --------------------------------------------------------------------- http://research.iiit.ac.in/~rehman
