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FItz - Error when processing images from pdf to html #1389
Description
Please provide all mandatory information!
Describe the bug (mandatory)
When page.get_text() function is applied to some pdfs that contain images, it returns the image turned upside down + it adds a black image with the same size as the original image behind it. This does not happen to other documents.
To Reproduce (mandatory)
I attach two documents:
-
document_OK.pdf --> document where the error does not happen
document_OK.pdf -
document_ERROR.pdf --> document where the error happens.
document_ERROR.pdf
In order to reproduce the error, please run the following code:
`
import fitz
file_ok = 'document_OK.pdf'
file_error = 'document_ERROR.pdf'
doc_ok = fitz.open(file_ok)
doc_error = fitz.open(file_error)
html_text_ok = ''
for page in doc_ok:
html_text_ok += page.get_text("html")
html_text_error = ''
for page in doc_error:
html_text_error += page.get_text('html')
`
Expected behavior (optional)
The expected behavior is the following:
Which generates the image in base64 in the document image_base64_OK.txt and the html in the file document_OK.txt (it is not permitted to upload html files, so I attach it as txt).
document_OK.txt
image_base64_OK.txt
However, the image in document_ERROR.pdf is converted to two images:
- A black rectangle.
- The image in the pdf turned upside down.
I also attach the base64 files of both images and the html file generated by fitz, document_ERROR.txt (again, I attach it as txt despite it is a html file).
document_ERROR.txt
image_ERROR1.txt
image_ERROR2.txt
Screenshots (optional)
Screenshots added in the previous section.
Your configuration (mandatory)
Operating system: MacOS 12.0.1
Python and PyMuPDF versions:
3.8.12 (default, Oct 22 2021, 18:39:35)
[Clang 13.0.0 (clang-1300.0.29.3)]
darwin
PyMuPDF 1.19.1: Python bindings for the MuPDF 1.19.0 library.
Version date: 2021-10-23 00:00:01.
Built for Python 3.8 on darwin (64-bit).
Additional context (optional)
Of course, I am aware that the problem might come from the pdf, but I don't really know why the image is recognized as two images and one of them is turned upside down.
I would really appreciate if you give me some insights on how to solve this. Thanks a lot!
Activity
JorjMcKie commentedon Nov 11, 2021
First of all I have to mention, that I cannot do anything about (X)HTML / XML output, because these are direct wrappers of MuPDF code.
But apart from that:
The error PDF is really a weird thing: if you look at the list
page.get_images()you will see 2 items, one at xref 25, one at xref 26. Both have the same image dimensions and both are displayed at the same bbox on the page - one (26) over the other(25).This is why you cannot see xref 25 in the PDF display.
But img 25 simply is a black rectangle, which you see when you save the pixmap
fitz.Pixmap(doc, 25).Image 26 is indeed stored as an upside down image - again try and save
fitz.Pixmap(doc, 26).So the page neutralizes this fact before it display the image. This can bee seen right at the beginning of the page's
/Contentsobject - looks like this:You can also verify this in Python directly:
All that is being however ignored by the html output - I have no idea why!
BTW the page looks quite ok apart from the upside down image. The black image is there, but invisible.
Interesting: If you convert the page to an SVG
page.get_svg_image(...)(which can also be displayed by browsers) then the image is correct 🤔!So what can you do?