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  1. JDK
  2. JDK-6335287

getImage is slow in linux

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    Details

    • Type: Enhancement
    • Status: Closed
    • Priority: P3
    • Resolution: Cannot Reproduce
    • Affects Version/s: 5.0
    • Fix Version/s: None
    • Component/s: client-libs
    • Labels:
    • Subcomponent:
      2d
    • CPU:
      x86
    • OS:
      linux

      Description

      A DESCRIPTION OF THE REQUEST :
      Image loading using Toolkit.getImage is 30-80% slower in Linux Java (1.5.0_05) than in Windows Java for large images, even if windows java is running in wine (windows emulator) in Linux (!!!). Both JPEG and PNG loading are slower.

      JUSTIFICATION :
      Waiting is always painful, especially in case of a slideshow program. Although JPEG reading is much faster in java 1.5 than in 1.4, it is still slow compared to windows java.

      EXPECTED VERSUS ACTUAL BEHAVIOR :
      EXPECTED -
      There should be no speed difference. Linux java should use the same, faster JPEG and PNG readers as windows java.
      ACTUAL -
      Test results:
      - GetImageTest with empty 15000x1000 JPEGs generated using imageio:
        12.19s P4 2.4GHz, SuSE Linux 10 RC1, Java 1.5.0_05-linux
         6.85s P4 2.4GHz, wine20050725/SuSE Linux 10 RC1, Java 1.5.0_05-win
        (first column is the runtime in seconds)
      - GetImageTest with empty 15000x1000 PNGs generated using imageio:
        9.514s P4 2.4GHz, SuSE Linux 10 RC1, Java 1.5.0_05-linux
        7.266s P4 2.4GHz, wine20050725/SuSE Linux 10 RC1, Java 1.5.0_05-win
      - loading some digital photos (large panorama images, JPEG) with SlideProject, a java slideshow program:
        31.2s P4 3.0GHz, SuSE Linux 9.1, Java 1.5.0_05-linux
        19.9s P4 3.0GHz, Windows XP, Java 1.5.0_05-win
        40.2s P4 2.4GHz, SuSE Linux 10 RC1, Java 1.5.0_05-linux
        29.8s P4 2.4GHz, wine20050725/SuSE Linux 10 RC1, Java 1.5.0_05-win

      ---------- BEGIN SOURCE ----------
      CreateImages.java - program for creating the large test JPEGs:

      import java.awt.image.BufferedImage;
      import java.util.Iterator;
      import java.io.*;
      import java.nio.MappedByteBuffer;
      import java.nio.channels.FileChannel;
      import javax.imageio.*;
      import javax.imageio.stream.ImageOutputStream;
      public class CreateImages {
          public static void main(String[] args) throws Exception {
              // create jpg files by default or png if it is specified in first arg
              String fmt = args.length != 0? args[0] : "jpg";
              // create empty 15000x1000 image file b0.jpg or b0.png
              int[] pixels = new int[15000];
              BufferedImage im = new BufferedImage(15000, 1000,
                                                   BufferedImage.TYPE_INT_RGB);
              Iterator it = ImageIO.getImageWritersByFormatName(fmt);
              ImageWriter wr = (ImageWriter)it.next();
              ImageOutputStream ios = ImageIO.createImageOutputStream(
                      new File("b0."+fmt));
              wr.setOutput(ios);
              wr.write(null, new IIOImage(im, null, null), null);
              ios.flush();
              wr.dispose();
              ios.close();
              // create b1.jpg, ..., b9.jpg files by copying b0.jpg
              for(int i = 1; i < 10; ++i) {
                  FileChannel in = new FileInputStream("b0."+fmt).getChannel();
                  FileChannel out = new FileOutputStream("b"+i+"."+fmt).getChannel();
                  long size = in.size();
                  MappedByteBuffer buf = in.map(FileChannel.MapMode.READ_ONLY, 0, size);
                  out.write(buf);
                  in.close();
                  out.close();
              }
          }
      }

      GetImageTest.java - the test program:

      import java.awt.*;
      import java.io.File;
      import javax.swing.*;
      public class GetImageTest extends JFrame {
          static final String[] DEFAULT_FILENAMES = new String[] {
              "b0.jpg", "b1.jpg", "b2.jpg", "b3.jpg", "b4.jpg",
              "b5.jpg", "b6.jpg", "b7.jpg", "b8.jpg", "b9.jpg"};
          JTextArea txt;
          GetImageTest(int nrows) {
              super("GetImageTest");
              setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
              getContentPane().setLayout(new GridLayout());
              getContentPane().add(txt = new JTextArea(nrows, 80));
              txt.setFont(new Font("Monospaced", Font.PLAIN, 12));
              pack();
          }
          int getImage(String fname) throws InterruptedException {
              Thread.sleep(500); // 0.5s rest before start
              long t0 = System.currentTimeMillis();
              Image im = getToolkit().getImage(fname); // load image
              MediaTracker mt = new MediaTracker(this);
              mt.addImage(im, 0);
              mt.waitForAll();
              int t = (int)(System.currentTimeMillis() - t0); // milliseconds elapsed
              txt.append(String.format("%.3f %3.1fM %4.1fMpix %5dx%-4d %s\n",
                         0.001*t, (new File(fname).length())/1048576.0,
                         1e-6*im.getWidth(null)*im.getHeight(null),
                         im.getWidth(null), im.getHeight(null), fname));
              return t;
          }
          public static void main(String[] args) throws Exception {
              String[] fnames = args.length != 0? args : DEFAULT_FILENAMES;
              GetImageTest w = new GetImageTest(fnames.length + 2);
              w.setVisible(true);
              int tot = 0; // total time elapsed in milliseconds
              for(int i = 0; i < fnames.length; ++i) {
                  int t = w.getImage(fnames[i]);
                  tot += t;
              }
              // print total time elapsed in seconds
              w.txt.append(String.format("%.3f", 0.001*tot));
          }
      }
      ---------- END SOURCE ----------

      CUSTOMER SUBMITTED WORKAROUND :
      Buying an 80% faster computer or trying to use the windows JVM with wine instead of the native linux JVM.

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              Assignee:
              tdv Dmitri Trembovetski (Inactive)
              Reporter:
              ndcosta Nelson Dcosta (Inactive)
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