Processing PDF Files (Enhanced)

Limina supports scanning PDF files for PII and creating de-identified or redacted copies. Limina’s supported entity types function across each file type, with localized variants of different PII (Personally Identifiable Information) entities, PHI (Protected Health Information) entities, and PCI (Payment Card Industry) entities being detected. Our Supported Languages and Supported Entity Types page provides a more detailed look.

If you’d like to try it yourself, please sign up for an account to get a free API key.

How PDFs Are Processed (Enhanced)

PDFs are processed as follows:

First, the PDF pages are scanned for text as well as Object Entities using OCR.
The detected objects are replaced with white boxes, and in-place replacements are done for the text.
PDF Metadata as well as any included attachments are removed from the PDF.
A new PDF is returned with the in-place replacements and without any attachments.

Parameters

Below are the parameters that control the behaviour of the PDF De-identifier. These parameters shall be specified under pdf_options.

Parameter	Explanation	Default
`approach`	This parameter changes which PDF approach is used.	”standard”
`use_inline_replacement`	This parameter sets whether in-line replacements should be made to the PDF. If set to `False`, the container will use the approach selected in `image_options.masking_method`	True
`density`	PDFs are converted into images using this DPI value. Smaller values result in images with smaller resolutions, which will take up less storage space and process faster, at the cost of output quality & redaction accuracy.	200
`element_types_to_process`	This parameter controls which elements in a PDF file are processed. If not set, all elements will be deidentified. Leaving out hyperlinks preserves the hyperlinks in the PDF.	[“page_contents”, “hyperlinks”]

PDF Approaches shows the differences between Standard and Enhanced PDF processing.

About the `element_types_to_process` parameter:

Not set (default): all elements are de-identified.
To preserve hyperlinks, leave it out. Hyperlinks, including both the visible link text and the underlying URL, are kept exactly as they appear in the original PDF.

Preserved hyperlinks are not checked for PII. Preserving hyperlinks keeps every hyperlink unchanged, including any PII it contains (for example, names or emails in a URL).

Support Matrix

	CPU Container	GPU Container	Community API	Professional API
Supported	Yes	Yes	No	No

Sample Request

Connect with one of our privacy experts to run this code.

{
  "file": {
    "data": "<file_content_base64>",
    "content_type": "application/pdf"
  },
  "entity_detection": {
    "return_entity": true
  },
  "pdf_options": {
    "approach":"enhanced"
  }
}

echo '{
          "file": {"data": "'$(base64 -w 0 sample.pdf)'", 
          "content_type": "application/pdf"}, 
          "entity_detection": {"return_entity": "True"},
          "pdf_options": {"approach": "enhanced"},
      }' \
| curl --request POST --url 'https://api.getlimina.ai/community/v4/process/files/base64' \
       -H 'Content-Type: application/json' \
       -H 'x-api-key: <YOUR KEY HERE>' \
       -d @- \
       | jq -r .processed_file \
       | base64 -d > 'sample.redacted.pdf'

import requests
import base64

file_url = "https://paidocumentation.blob.core.windows.net/$web/sample.pdf"
filename_out = "/path/to/output/sample.redacted.pdf"
file_content = requests.get(file_url).content
file_content_base64 = base64.b64encode(file_content).decode()

url = "https://api.getlimina.ai/community/v4/process/files/base64"

headers = {"Content-Type": "application/json", "x-api-key": "<INSERT API KEY>"}

payload = {
  "file":{
    "data": file_content_base64,
    "content_type": "application/pdf",
  },
  "entity_detection": {
    "return_entity": True
  },
  "pdf_options": {
    "approach": "enhanced"
  }
}

response = requests.post(url, json=payload, headers=headers)
with open(filename_out, "wb") as f:
    f.write(base64.b64decode(response.json()["processed_file"]))

from privateai_client import PAIClient
from privateai_client.objects import request_objects
import base64

filename_in = "sample.pdf"
filename_out = "sample.redacted.pdf"

file_type= "application/pdf"
client = PAIClient(url="https://api.getlimina.ai/community/v4/", api_key="<YOUR API KEY>")

with open(filename_in, "rb") as b64_file:
    file_data = base64.b64encode(b64_file.read())
    file_data = file_data.decode("ascii")

file_obj = request_objects.file_obj(data=file_data, content_type=file_type)
request_obj = request_objects.file_base64_obj(file=file_obj)
resp = client.process_files_base64(request_object=request_obj)

with open(filename_out, 'wb') as redacted_file:
    processed_file = resp.processed_file.encode("ascii")
    processed_file = base64.b64decode(processed_file, validate=True)
    redacted_file.write(processed_file)

Sample Response

Response

{
  "processed_file": "Base64 Encoded File Content of the Redacted File",
  "processed_text": "string",
  "entities": "List[Entity]",
  "entities_present": true,
  "languages_detected": {"lang_1": 0.67, "lang_2": 0.74}
}

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Processing PDF Files (Enhanced)

How PDFs Are Processed (Enhanced)

Parameters

About the `element_types_to_process` parameter:

Support Matrix

Sample Request

Sample Response

​How PDFs Are Processed (Enhanced)

​Parameters

​About the element_types_to_process parameter:

​Support Matrix

​Sample Request

​Sample Response

How PDFs Are Processed (Enhanced)

Parameters

About the `element_types_to_process` parameter:

Support Matrix

Sample Request

Sample Response