Export JPanel to vector graphics

Question

I would like to export the image in my JPanel to a vector graphics file so it can be edited and printed at a higher-than-screen resolution. Essentially I want its paint() function to be called with a destination Graphics that saves the drawing commands into a vector graphic file.

What is a good, simple way to do this? What libraries are recommended? Which vector format would be best, and why?

Answer 1

Apache Batik will let you paint to a specialised implementation of a Graphics2D object and then export as an scalable vector graphics (.svg) file. You can then view/process/print it using an SVG-enabled browser (Firefox will handle it nativly, ISTR, IE and others can use plugins).

See the SVGGraphics2D object (process documented here)

Answer 2

this is basically not possible directly, as the low level java api works in terms of raster (pixels) and is never stored in vector format. (Check the API of java.awt.Graphics to see what I mean).

there are some general purpose program that convert raster to vector formats, this is one I found on a quick search: http://autotrace.sourceforge.net/index.html

so, using such a program you can divide your problem into two smaller problems:

1. convert your JPanel into a bitmap or file (http://www.jguru.com/faq/view.jsp?EID=242020)
2. run autotrace on the file.

Answer 3

Have a look at The Java EPS Graphics2D package.

Many Java programs use Graphics2D to draw stuff on the screen, and while it is easy to save the output as a png or jpeg file, it is a little harder to export it as an EPS for including in a document or paper.

This package makes the whole process extremely easy, because you can use the EpsGraphics2D object as if it's a Graphics2D object. The only difference is that all of the implemented methods create EPS output, which means the diagrams you draw can be resized without leading to any of the jagged edges you may see when resizing pixel-based images, such as JEPG and PNG files.

Answer 4

The Java EPS mentioned by Pierre looks good, but if it isn't you might also like to look at FreeHEP Vector Graphics. Written to allow Java reuse in the High Energy Physics field it includes a vector graphics package, done through an implementation of Graphics2D. We've used it to export EPS very successfull for a number of years.