Export annotation

[aathi271991]

Hello,

I need clarification on how to export annotations after drawing and obtaining coordinates within this viewer. I have attached images for reference.

Thank you!

[stephanrauh]

Are you looking for pdfViewerService.getSerializedAnnotations()?

[aathi271991]

If I draw a box in an "Adobe Acrobat PDF file", I want to get the text 'Adobe Acrobat PDF file' that I draw over.

[aathi271991]

I need to extract the text inside a rectangular zone that I draw within a PDF.

[stephanrauh]

That's not easy:

• Many PDF documents aren't really texts. They are just scanned images. In that case, you need an OCR tool.
• If the PDF document contains text, activate the text layer. After drawing the box, the DOM consists of three layers. The bottom-most layer is the canvas. That's the text you see. Above that, there's a text layer. It's invisible unless you select text with the mouse. The box is another layer, the annotation editor layer. The box is inside a rectangular area that's slightly larger than the drawing. Get the coordinates of the box and find all the <span> tags at the same position. Concatenate the innerText of these <span> tags, and you've got your text.

Note that this approach does not copy images. I suppose it'll also fail with forms. The text layer only contains the text. Adding insult to injury, the text position is slightly off, but usually it's close enough so you won't notice.

[Faryal13]

@stephanrauh Why are we returning the id null in getSerializedAnnotations(), I have scenario where i am storing all the annotation in backend and when load again then loading all the already created annotation but when user done with adding more and call getSerializedAnnotations() it is returning me all the annotation which is right but how will I identify that user have created newly which dnt exists in my database ,id would be helpful to identify it

[stephanrauh]

I've inherited this functionality from @calixteman, who kindly implemented it in pdf.js. I know hardly anything about how getSerializedAnnotations() works internally. I only expose this API because it might be useful to you, but you're using it at your own risk, and the showcase explicitly states the the API may break without notice.