打印缓冲区到打印机

Question

我有一个应用程序，我想从中打印图像。图像将作为BufferedImage对象加载。问题是，当我打印图像（到postscript或pdf文件）时，质量真的很差
当我使用一些其他工具（基本上是任何可以打印图像的图片查看器应用程序）时，结果会明显更好
我知道DPI和分辨率可能会有一些问题，但我不确定如何计算正确的打印值
我试着在谷歌上搜索并尝试了一些方法，但似乎没有像我预期的那样奏效。Basicaly我只想将图像（分辨率为3000x2000）打印到打印机上（DPI为600x600）。

这就是我创建打印作业的方式：

PrintRequestAttributeSet printAttributes = new HashPrintRequestAttributeSet();
printAttributes.add(PrintQuality.HIGH);
printAttributes.add(new PrinterResolution(600, 600 PrinterResolution.DPI)); 
printAttributes.add(new Destination(URI.create("file:/tmp/test.ps")));
PageFormat pf = printerJob.defaultPage();
Paper paper = pf.getPaper();
double xMargin = 0.0;
double yMargin = 0.0;
paper.setImageableArea(xMargin, yMargin, paper.getWidth() - 2 * xMargin, paper.getHeight() - 2 * yMargin);
pf.setPaper(paper);
// create new Printable for the specified image
printerJob.setPrintable(PrintableImage.get(image), pf)
if (printerJob.printDialog(printAttributes)) {
    printerJob.print(printAttributes);
}

其中image是BufferedImage和PrintableImage.get返回实现Printed的新实例然后实际的打印是这样做的（我让我尝试过但对我不起作用的注释代码）

@Override
public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {
if (image == null)
    throw new PrinterException("no image specified to be printed");
// We have only one page, and 'page' is zero-based
if (pageIndex > 0) {
    return NO_SUCH_PAGE;
}
// tranlate the coordinates (according to the orientations, margins, etc)
Graphics2D printerGraphics = (Graphics2D) graphics;
//g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
//g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
//g.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
printerGraphics.translate(pageFormat.getImageableX(), pageFormat.getImageableY());
// THIS IS A TEST - javax.printing api uses 72 DPI, but we have 600DPI set for the printer
//AffineTransform at = printerGraphics.getTransform();
//printerGraphics.scale((double)72 / (double)600, (double)72 / (double)600);
//printerGraphics.drawRenderedImage(image, null);
//printerGraphics.setTransform(at);
//if(printerGraphics != null)
    //return PAGE_EXISTS;
double scale = 72.0 / 600.0;
Dimension pictureSize = new Dimension((int)Math.round(image.getWidth() / scale), (int) Math.round(image.getHeight() / scale));

// center the image horizontaly and verticaly on the page
int xMargin = (int) ((pageFormat.getImageableWidth() - image.getWidth()) / 2);
int yMargin = (int) ((pageFormat.getImageableHeight() - image.getHeight()) / 2);
xMargin = yMargin = 0;
System.out.println(String.format("page size [%.2f x %.2f], picture size [%.2f x %.2f], margins [%d x %d]", pageFormat.getImageableWidth(), pageFormat.getImageableHeight(), pictureSize.getWidth(), pictureSize.getHeight(), xMargin, yMargin));
printerGraphics.drawImage(image, xMargin, yMargin, (int)pageFormat.getWidth(), (int)pageFormat.getHeight(), null);
//printerGraphics.drawImage(image, 0, 0, null);
//printerGraphics.drawImage(image, xMargin, yMargin, pictureSize.width, pictureSize.height, null);
//printerGraphics.drawImage(image, xMargin, yMargin, (int) pageFormat.getImageableWidth(), (int) pageFormat.getImageableHeight(), 0, 0, pictureSize.width, pictureSize.height, null);
//printerGraphics.drawImage(image, 0, 0, (int) pageFormat.getWidth() - xMargin, (int) pageFormat.getHeight() - yMargin, 0, 0, pictureSize.width, pictureSize.height, null);
return PAGE_EXISTS;
}

有人能解决同样的问题吗
如有任何帮助，我们将不胜感激
谢谢
Matej

Answer 1

我就是这么做的。它运行得很顺利。请注意，这个代码片段并没有使图像居中。

public int print(Graphics g, PageFormat pageFormat, int pageIndex) throws PrinterException {
                if (pageIndex > 0) {
                    return (NO_SUCH_PAGE);
                } else {
                    double pageHeight = pageFormat.getImageableHeight(), pageWidth = pageFormat.getImageableWidth();
                    Graphics2D g2d = (Graphics2D) g;
                    g2d.translate(pageFormat.getImageableX(), pageFormat.getImageableY());
                    if (pageHeight < image.getHeight() || pageWidth < image.getWidth()) {
                        g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
                                RenderingHints.VALUE_INTERPOLATION_BILINEAR);
                        g2d.drawImage(image, 0, 0, (int) pageWidth, (int) pageHeight - textSize, null);
                    } else {
                        g2d.drawImage(image, 0, 0, null);
                    }
                    g2d.dispose();
                    return (PAGE_EXISTS);
                }
            }

Answer 2

@Viktor Fonic谢谢你，我搜索了很多来做这件事！您的解决方案运行良好，但有一个小错误，text未声明大小，因此：

int textSize =  (int) (pageHeight - image.getHeight()*pageWidth/image.getWidth());