Description Daniel Krügler 2005-04-21 06:01:08 EDT

I observered remarkable bad performance of org.eclipse.swt.graphics.ImageData
loading JPG images. E.g. an ~120 kB JPG file (1455 x 1604 Pixels, 16,7 Millions
colors (24 BitsPerPixel)) needs several **seconds** for just the single line

Image img = new Image(getDisplay(), getFileName());

The lack of performance does not depend whether the image is already in memory
or loaded from other locations (e.g. file). Simple debugging shows, that the
bottleneck seems to be located during operation in
org.eclipse.swt.internal.image.JPEGFileFormat.loadFromByteStream(), i.e. even an
in-memory file provided by the example

  final byte[] data = ..; // Get image data
  final InputStream is = new ByteArrayInputStream(data);
  try {
    final ImageData imgData = new ImageData(is); // bottle neck!!
    final ImageDescriptor d = ImageDescriptor.createFromImageData(imgData);
    fMyImage = d.createImage(true);
  } finally {
    is.close();
  }

from newsgroup contribution "Inefficient image loadings?" in eclipse.platform.swt.

Daniel Krügler