Re: Getting an image with JLink
- To: mathgroup at smc.vnet.net
- Subject: [mg116806] Re: Getting an image with JLink
- From: Rebecca Miller-Webster <rebecca at graciouseloise.com>
- Date: Tue, 1 Mar 2011 05:20:40 -0500 (EST)
Hi,
Thanks. I really need to call Mathematica from Java so your example doesn't
quite work. However, I took your suggestion of saving the image to a file
and that was successful ... and seems to be much faster.
Thanks,
Rebecca
On Sun, Feb 27, 2011 at 4:35 AM, David Bailey <dave at removedbailey.co.uk>wrote:
> On 25/02/2011 11:37, Rebecca Miller-Webster wrote:
> > Hi,
> >
> > I am writing a Java program to get an image (or byte array) from a
> > Mathematica program.
> >
> > My Java code looks something like this:
> >
> > ml.evaluate("tmp = renderImageGenericLig[" + sampleFormId + ", noteText,"
> +
> > sizeX + "," + sizeY + ", margin," + dpi + "," + lineStep + "," + tabStep
> +
> > "," + ligatureMatch + "," + maxLigHeightDiff + "," + mmSearch + "," +
> > highToLowGap + "," + lowToHighGap + "," + wordBaselineVariance + "," +
> > debugFlag + "]");
> >
> > ml.discardAnswer();
> > byte[] res = ml.evaluateToImage("tmp", 0, 0);
> >
> > try {
> > BufferedImage imag = ImageIO.read(new
> > ByteArrayInputStream(res));
> > //BufferedImage imag = ImageIO.read(new
> InputStream(res));
> > if(imag != null) {
> > ImageIO.write(imag, "jpg", new
> > File("/Users/Rebecca/","test.jpg"));
> > }else {
> > System.out.println("image is null");
> > }
> > } catch (IOException ex) {
> > System.out.println("IOException occurred: " +
> > ex.getMessage());
> > }
> >
> >
> > The renderImageGenericLig function is returning:
> >
> > Return [ Graphics[Raster[ note1[[1]] ], AspectRatio -> Automatic,
> > ImageSize -> 530 ] ];
> >
> >
> > Note: I've also tried returning just Raster as well as Image[Graphics ...
> >
> >
> > In debug mode, from a notebook, I can render the image using:
> >
> > Print[ Graphics[Raster[ note1[[1]] ], AspectRatio -> Automatic,
> > ImageSize -> 530 ] ];
> >
> >
> > However, when I check the saved file, it is just a white image with
> nothing
> > in it. When debugging the Java code, I see to be getting data in the
> byte
> > array, but when I convert to image with Java, I just end up with 0s or
> 1s.
> >
> >
> > I don't know Mathematica very well and I am having a hard time finding
> > examples of JLink in Java connecting to Mathematica. Any help would be
> > appreciated.
> >
> >
> > Thanks!
> >
> > Rebecca
> >
> Wow - that looks a lot of work. J/Link lets you do things a lot easier
> than that. Say you have a static class in your Java code called foo,
> that takes a string argument, you can call it with:
>
> LoadJavaClass["something.something.MyClass"];
> something`something`MyClass.foo["xxxxx.jpg"];
>
> (No Mathlink code in sight)
>
> Although it is possible to pass the image directly, it is better, I find
> to put the image in a file and pass the name of the file.
>
> Alternatively, if your aim is to create a Java GUI, you might want to
> try my free Super Widget Package, available from my website.
>
> David Bailey
> http://www.dbaileyconsultancy.co.uk
>
>