I am facing a problem extracting images with their labels (not metadata!) from pdf files. By label I mean the text that is assigned to the image to describe it regeardless of it's possition, underneath or above. I've tried alot of known parsers, such as iText, Tika, PDFbox and pdf2html but i found no way of how to do this. Any suggestions?
Related
Noticed that images sometimes are sliced up in PDFs.
Steps:
insert an image with a high resoultion (3000x1800) into a .docx
use "Microsoft Print to PDF" option of Word to convert to PDF
extracting all images with pdfimages or pymupdf
Result:
Image is sliced horizontally into three images
Questions:
What exactly happens in the in the transition from .docx to pdf (or in generell in the process to pdf) that makes the converter slice it up into three images instead of one?
Do the individuell XObjects of the sliced images contain information which says that these three images belong to originally one?
How do I know how the images are sliced (horizontally / vertically) and what if originally there were two images inserted into the .docx file and both of them are sliced. Can you tell if slice x belongs to original image y or z?
So, as you have found out: because the code which generates the PDF choose to do so.
The technical reasons may be various - it could be that historically there were printers which would only have so much memory, and would need to get limiterd size-images when printing, and someone at some point when writing the PDF export code present in Microsoft Office choose to apply this limit.
Anyway, technically, as put in the comments, an image in a PDF file could be composed of unlimited smaller images collated together.
Now, the second part, and your actual question: to know whether images ibn a PDF file belong together in a single original image one would need a custom extractor tool to check the geometry of all images in the document and find out which images have no margins or boundaries with others - it would not be that hard to do for well behaved files (which we can't know if MS Office generated files are: there are ways to obfuscate image positioning by making it indirectly). The metadata in the image-parts may or may not contain information that would allow one to recompose the original image: it would be up to the code generating the PDF to include this metadata or not - but the geometry can't lie in this case: if the final document presents a single image visually, it is possible to detect that when fetching the images.
I'm working with fastai, trying to pass some images to a dataloader. The original images are kind of pinkish, but after passing them they appear mostly as green-black (see image in link below):
Original pinkish image (up) and example images (down) after passing them to dataloader, and the code.
The code I've used for the datablock and to show the images is:
example = DataBlock(
blocks=(ImageBlock, CategoryBlock),
get_items=get_image_files,
splitter=GrandparentSplitter(),
get_y=parent_label,
item_tfms=Resize(128)) #already tried it without item_tfms just in case, still black-green
dls = example.dataloaders(path)
dls.show_batch(nrows=1, ncols=3)
I tried with .tif and .jpeg images, and both show the same problem. The only thing that comes to my mind is that somewhat somewhere is not reading correctly the color format (RGB according to my original files), or maybe transforming it; but I'm not able to figure it out.
Just in case it's important, I'm working in a Jupyter notebook with a MackBook Air M1.
Thanks!
Irene
I have pdf with tables and cells and i have added paragraph with formatted text in the cell, i need to read list of all tables and followed by text in paragraph with some css(some text highlighted in color), let me know how to start with this, any link where i can go through.
Using iText7
Thanks
Daya
These are lots of pages to go through CSS, use them and get a bit known about CSS. W3SCHOOLS is a good place to go through them :)
i have converted PDF to xlsx - which helped in identifying font size,color,name.
I am using AsciiDoc with Asciidoctor Gradle Plugin to generate technical documentation as PDF.
When I used M$ Word, I could easily place forms on an image, for example
colored rectangles,
boxes with numbers or
even links to sections within the document,
to better point out interesting areas within the image.
Example:
On the example image I have placed two rectangles and each one contains a link (starting with the word «Dialogbereich») leading to a other sections within the document.
Is it possible to achieve something like this (directly) in AsciiDoc?
Note that the answers to asciidoc: how to add callouts asciidoc to image do not apply here as the Asciidoctor PDF backend does not use DocBook to generate the PDF.
I know I could create a layered image in GIMP to at least place the rectangles. However, that wouldn't help me with the links.
I've read much about PDF extractions and libraries (as iText) but i just haven't found a solution to extract images and text (with coordinates) from a PDF.
The task is to scan PDF with catalog of products and extract each image. There is an image code printed next to each image and also a list of product codes for products that are shown on the image.
I know that there is no way to extract structured info from a PDF like this but with coordinates of all image and text objects I could write code to identify linked text by its distance from the image. Then I could split text using a RegExp and find out what is a product code, what is an image code etc.
Could you recommend a good and working solution for the task?
Use XPDF (http://www.foolabs.com/xpdf/)
It can extract all the characters in the PDF with co-ordinates (pdftotext -bbox [sourcefile] [outputfile]) and also all the images and SVGs in the PDF.
It's open source (GPLv2) and supports a lot of additional extraction functionalities as well.
Several Java libraries can do this. Have you looked at JPedal or PdfBox?
If a commercial library is an option for you, you could try Amyuni PDF Creator .Net or Amyuni PDF Creator ActiveX. You could use the method IacDocument.GetObjectsInRectangle to retrieve all the "graphic objects" of your interest, then use the ObjectType attribute to separate images from text. The library already provides an algorithm for putting close text together. From the documentation:
IacDocument.GetObjectsInRectangle Method
The GetObjectsInRectangle method gets all the objects that are in the specified rectangle.
Usual disclaimer applies.