Rendering slideshows, WMF, EMF and EMF+Please be aware, that the documentation on this page reflects the current development, which might not
have been released. If you rely on an unreleased feature, either use a
nightly development build or feel free to ask on the
mailing list for the release schedule.Rendering slideshows, WMF, EMF and EMF+
For rendering slideshow (HSLF/XSLF), WMF, EMF and EMF+ pictures, POI provides an utility class
PPTX2PNG:
Options:
-scale scale factor
-fixSide specify side (long,short,width,height) to fix - use as amount of pixels
-slide 1-based index of a slide to render
-format png,gif,jpg,svg,pdf (log,null for testing)
-outdir output directory, defaults to origin of the ppt/pptx file
-outfile output filename, defaults to "${basename}-${slideno}.${format}"
-outpat output filename pattern, defaults to "${basename}-${slideno}.${format}"
patterns: basename, slideno, format, ext
-dump dump the annotated records to a file
-quiet do not write to console (for normal processing)
-ignoreParse ignore parsing error and continue with the records read until the error
-extractEmbedded extract embedded parts
-inputType default input file type (OLE2,WMF,EMF), default is OLE2 = Powerpoint
some files (usually wmf) don't have a header, i.e. an identifiable file magic
-textAsShapes text elements are saved as shapes in SVG, necessary for variable spacing
often found in math formulas
-charset sets the default charset to be used, defaults to Windows-1252
-emfHeaderBounds force the usage of the emf header bounds to calculate the bounding box
-fontdir (PDF only) font directories separated by ";" - use $HOME for current users home dir
defaults to the usual plattform directories
-fontTtf (PDF only) regex to match the .ttf filenames
-fontMap Instructions to run
JDK 1.8 is by default using the PiscesRenderingEngine and affected by
Busy loop hangs.
To workaround this, use the MarlinRenderingEngine which is experimental provided starting from
openjdk8u252 (JDK-8143849)
via -Dsun.java2d.renderer=sun.java2d.marlin.MarlinRenderingEngine or for older jdk builds,
preload the marlin jar.
Integrate rendering in your code#1 - Use PPTX2PNG via file or stdin
For file system access, you need to save your slideshow/WMF/EMF/EMF+ first to disc and then call
PPTX2PNG.main()
with the corresponding parameters.
for stdin access, you need to redirect System.in before:
#2 - Render WMF / EMF / EMF+ via the *Picture classes 1500) {
width *= 1500/max;
height *= 1500/max;
}
BufferedImage bufImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
Graphics2D g = bufImg.createGraphics();
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
g.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);
wmf.draw(g, new Rectangle2D.Double(0,0,width,height));
g.dispose();
ImageIO.write(bufImg, "PNG", new File("bla.png"));
}
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#3 - Render slideshows directly ss = SlideShowFactory.create(file, null, true)) {
Dimension pgsize = ss.getPageSize();
int width = (int) (pgsize.width * scale);
int height = (int) (pgsize.height * scale);
for (Slide slide : ss.getSlides()) {
BufferedImage img = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
Graphics2D graphics = img.createGraphics();
// default rendering options
graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
graphics.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
graphics.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
graphics.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);
graphics.setRenderingHint(Drawable.BUFFERED_IMAGE, new WeakReference<>(img));
graphics.scale(scale, scale);
// draw stuff
slide.draw(graphics);
ImageIO.write(img, "PNG", new File("output.png"));
graphics.dispose();
img.flush();
}
}
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