org.im4java.core.CommandException: org.im4java.core.CommandException: convert.exe: WriteBlob Failed `-' @ error/png.c/MagickPNGErrorHandler/1804.
    at org.im4java.core.ImageCommand.run(ImageCommand.java:219)
    at com.zreflect.emyed.content.document.PDFtoImageConvertor.main(PDFtoImageConvertor.java:46)
Caused by: org.im4java.core.CommandException: convert.exe: WriteBlob Failed `-' @ error/png.c/MagickPNGErrorHandler/1804.
    at org.im4java.core.ImageCommand.finished(ImageCommand.java:253)
    at org.im4java.process.ProcessStarter.run(ProcessStarter.java:314)
    at org.im4java.core.ImageCommand.run(ImageCommand.java:215)
    ... 1 more

private static final String IMAGE_MAGIC_PATH = ConfigurationManager.getApplicationProperty(ConfigurationManager.IMAGEMAGIC_INSTALLATION_PATH);
     private static final int IMAGE_DENSITY = 300;
     private static final int IMAGE_RESIZE = 800;
     private static final double IMAGE_QUALITY = 300;
     private static final int IMAGE_WIDTH = 800;
     private static final int IMAGE_HEIGHT = 800;

    public static void main(String[] args) {
        ProcessStarter.setGlobalSearchPath(IMAGE_MAGIC_PATH);
        IMOperation op = new IMOperation();
        op.addImage();
        op.density(IMAGE_DENSITY);
        op.resize(IMAGE_RESIZE);
        op.quality(IMAGE_QUALITY);
        op.alpha("remove");
        op.resize(IMAGE_WIDTH,IMAGE_HEIGHT);
        op.background("white");
        op.colorspace("RGB");
        op.addImage("png:-");
        ConvertCmd cmd = new ConvertCmd();
        //cmd.setAsyncMode(true);
        ImageConversionListener listener = new ImageConversionListener();
        Stream2BufferedImage s2b = new Stream2BufferedImage();
        cmd.setOutputConsumer(s2b);
        ContentManager cm = new ContentManager();
        cmd.addProcessEventListener(listener);

        try {
            cmd.run(op, "C:\Users\Veera\Pictures\ImageMagic\Vendor Compliance Guide.pdf");
            BufferedImage img = s2b.getImage();
            cm.uploadImage(img, "test", null, true, false);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IM4JavaException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }