[PDFBOX-3885] Get wrong image location

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Not A Problem
• Affects Version/s: 2.0.7
• Component/s: Rendering
• Labels: how-to
• Environment: osx, java8
• Assignee: Andreas Lehmkühler
• Reporter: Sun Peter
• Created: 02/Aug/17 09:42
• Updated: 03/Aug/17 06:06
• Resolved: 02/Aug/17 10:25

Description

I'm using below code to extract images to an XML file.

public class ImageExtractor extends PDFStreamEngine {
    private List<Image> images = new ArrayList<>();

    public ImageExtractor() {
        addOperator(new Concatenate());
        addOperator(new DrawObject());
        addOperator(new SetGraphicsStateParameters());
        addOperator(new Save());
        addOperator(new Restore());
        addOperator(new SetMatrix());
    }

    /**
     * This is used to handle an operation.
     *
     * @param operator The operation to perform.
     * @param operands The list of arguments.
     * @throws IOException If there is an error processing the operation.
     */
    @Override
    protected void processOperator(Operator operator, List<COSBase> operands) throws IOException {
        String operation = operator.getName();
        if ("Do".equals(operation)) {
            COSName objectName = (COSName) operands.get(0);
            PDXObject xobject = getResources().getXObject(objectName);
            if (xobject instanceof PDImageXObject) {
                PDImageXObject image = (PDImageXObject) xobject;
                String name = objectName.getName();
                String format = image.getSuffix();
                Matrix ctmNew = getGraphicsState().getCurrentTransformationMatrix();
                float imageWidth = ctmNew.getScalingFactorX();
                float imageHeight = ctmNew.getScalingFactorY();
                // position in user space units. 1 unit = 1/72 inch at 72 dpi
                float x = ctmNew.getTranslateX();
                float y = ctmNew.getTranslateY();
                ByteArrayOutputStream bos = new ByteArrayOutputStream();
                BufferedImage bufferedImage = image.getOpaqueImage();
                ImageIO.write(bufferedImage, format, bos);
                images.add(new Image(x, y, imageWidth, imageHeight, name, format, bos.toByteArray()));
            }
        } else {
            super.processOperator(operator, operands);
        }
    }

    public byte[] toZipFile(PDDocument doc) throws IOException {
        int pageNum = 0;
        StringBuilder builder = new StringBuilder("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<document>\n");
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        ZipOutputStream zipOut = new ZipOutputStream(bos);
        try {
            for (PDPage page : doc.getPages()) {
                builder.append(String.format("<page width=\"%f\" height=\"%f\">\n", page.getBBox().getWidth(), page.getBBox().getHeight()));
                pageNum++;
                this.processPage(page);
                for (Image image : images) {
                    byte[] data = image.getData();
                    ZipEntry zipEntry = new ZipEntry(image.getName() + "." + image.getFormat());
                    zipOut.putNextEntry(zipEntry);
                    zipOut.write(data);

                    builder.append(String.format("<image x=\"%f\" y=\"%f\" width=\"%f\" height=\"%f\" name=\"%s\" format=\"%s\"></image>\n", image.getX(), image.getY(), image.getWidth(), image.getHeight(), image.getName(), image.getFormat()));
                }
                builder.append("</page>\n");
            }
            builder.append("</document>");
            System.out.println(builder);
            ZipEntry xmlFile = new ZipEntry("images.xml");
            zipOut.putNextEntry(xmlFile);
            zipOut.write(builder.toString().getBytes(Charset.defaultCharset()));
        } finally {
            zipOut.close();
        }
        return bos.toByteArray();
    }
}

Output is below. the y location is wrong. it should be 434.

<document>
<page width="595.000000" height="842.000000">
<image x="48.000000" y="108.000000" width="315.000000" height="300.000000" name="Im12" format="jpg"></image>
</page>
</document>

I got the right output with poppler.

<image top="434" left="48" width="315" height="300" src="src-1_1.jpg"/>