Convert PDF to Black and White (Grayscale)

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import logging
from fastapi import FastAPI, File, UploadFile, HTTPException
from fastapi.responses import HTMLResponse, StreamingResponse
from pydantic import BaseModel
import fitz  # PyMuPDF
from PIL import Image, ImageOps
import io

# Configure logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

app = FastAPI()

def convert_pdf_to_grayscale(pdf_stream):
    try:
        pdf = fitz.open("pdf", pdf_stream)  # Specify the filetype when opening the stream
        gray_pdf = fitz.open()  # Create a new PDF to store grayscale pages
        for page_number in range(len(pdf)):
            page = pdf[page_number]
            pix = page.get_pixmap()
            # Convert to grayscale
            gray_pix = fitz.Pixmap(pix, 0) if pix.alpha else fitz.Pixmap(fitz.csGRAY, pix)
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Frequently Asked Questions

What are some business applications for the Convert PDF to Black and White (Grayscale) app?

The Convert PDF to Black and White (Grayscale) app has several business applications: - Reducing printing costs by converting color PDFs to grayscale before printing - Improving readability of scanned documents by converting them to black and white - Preparing documents for fax transmission or older printing systems that only support black and white - Standardizing document appearance for professional presentations or archival purposes

How can this app improve document management processes in an organization?

The Convert PDF to Black and White (Grayscale) app can streamline document management by: - Reducing file sizes, making storage and sharing more efficient - Creating a consistent look for all documents, enhancing brand identity - Simplifying the digitization process for old documents - Ensuring compatibility with a wider range of devices and printers

What industries could benefit most from using the Convert PDF to Black and White (Grayscale) app?

Several industries can benefit from this app, including: - Legal firms dealing with large volumes of scanned documents - Educational institutions preparing course materials - Government agencies processing and archiving official documents - Publishing houses preparing manuscripts for print or e-book formats - Healthcare providers managing patient records and medical literature

How can I modify the Convert PDF to Black and White (Grayscale) app to include a watermark on each page?

To add a watermark to each page, you can modify the convert_pdf_to_grayscale function. Here's an example of how to do this:

```python def convert_pdf_to_grayscale(pdf_stream): try: pdf = fitz.open("pdf", pdf_stream) gray_pdf = fitz.open() for page_number in range(len(pdf)): page = pdf[page_number] pix = page.get_pixmap() gray_pix = fitz.Pixmap(pix, 0) if pix.alpha else fitz.Pixmap(fitz.csGRAY, pix) gray_page = gray_pdf.new_page(width=gray_pix.width, height=gray_pix.height) gray_page.insert_image(gray_page.rect, pixmap=gray_pix)

           # Add watermark
           watermark_text = "Confidential"
           gray_page.insert_text((50, 50), watermark_text, fontsize=20, color=(0.5, 0.5, 0.5))

       return gray_pdf
   except Exception as e:
       logger.error(f"Failed to convert PDF to grayscale: {e}")
       raise HTTPException(status_code=500, detail="Failed to convert PDF to grayscale.")

```

This modification adds a "Confidential" watermark to the top-left corner of each page.

Can the Convert PDF to Black and White (Grayscale) app be extended to support other file formats?

Yes, the app can be extended to support other file formats. You would need to add new conversion functions for each format and modify the /upload_pdf endpoint to handle different file types. Here's an example of how you could extend the app to support image files:

```python from PIL import Image

@app.post("/upload_file") async def upload_file(file: UploadFile = File(...)): if file.content_type.startswith('image/'): # Handle image files image = Image.open(io.BytesIO(await file.read())) grayscale_image = ImageOps.grayscale(image) img_byte_arr = io.BytesIO() grayscale_image.save(img_byte_arr, format='PNG') img_byte_arr.seek(0) return StreamingResponse(img_byte_arr, media_type="image/png") elif file.content_type == 'application/pdf': # Existing PDF handling code ... else: raise HTTPException(status_code=400, detail="Unsupported file type.") ```

This modification allows the app to convert both PDF and image files to grayscale, expanding its functionality beyond just PDFs.

Created: | Last Updated:

An app that converts uploaded PDF files to black and white (grayscale) and allows for easy downloading of the converted file.

Introduction to the PDF to Grayscale Conversion Template

Welcome to the Lazy template guide for converting PDF files to grayscale. This template provides a simple and efficient way to upload a PDF file and receive a converted grayscale version. It's perfect for builders looking to integrate PDF processing capabilities into their applications without worrying about the complexities of deployment and environment setup.

Getting Started with the Template

To begin using this template, click on "Start with this Template" in the Lazy builder interface. This will pre-populate the code in your Lazy Builder interface, so you won't need to copy, paste, or delete any code manually.

Test: Deploying the App

Once you have the template loaded, press the "Test" button to start the deployment of your app. The Lazy CLI will handle the deployment process, and you won't need to install any libraries or set up your environment. The deployment process is fully managed by Lazy.

Using the App

After the deployment is complete, Lazy will provide you with a dedicated server link. You can use this link to access the FastAPI server that hosts your PDF to grayscale conversion service. Additionally, Lazy will provide a link to the FastAPI documentation, where you can find more details about the API endpoints and how to interact with them.

The main page of your app will serve as a simple user interface for uploading PDF files. Here's how to use it:

  • Open the provided server link in your web browser to view the main page.
  • You will see a form where you can upload a PDF file.
  • Select a PDF file from your device and click on "Convert to Grayscale".
  • Once the file is processed, a download link will appear, allowing you to save the converted grayscale PDF to your device.

Integrating the App

If you wish to integrate this PDF conversion service into another application or tool, you can use the API endpoints provided by the FastAPI server. Here's a sample request you might use to interact with the API programmatically:

`import requests



Replace 'your_server_link' with the link provided by Lazy after deployment

url = 'your_server_link/upload_pdf'

files = {'file': open('path_to_your_file.pdf', 'rb')}



response = requests.post(url, files=files)



if response.status_code == 200:

    with open('grayscale_pdf.pdf', 'wb') as f:

        f.write(response.content)

    print("Downloaded grayscale PDF")

else:

    print(f"Error: {response.status_code}")
` Remember to replace 'your_server_link' with the actual server link provided by Lazy and 'path_to_your_file.pdf' with the path to the PDF file you want to convert.









By following these steps, you can easily integrate the PDF to grayscale conversion service into your application, providing a valuable feature to your users with minimal effort.



Here are 5 key business benefits for this PDF to grayscale conversion template:

Template Benefits

  1. Cost Reduction in Printing: By converting color PDFs to grayscale, businesses can significantly reduce printing costs, especially for large documents or high-volume printing needs.

  2. Improved Document Readability: Grayscale conversion can enhance the readability of certain documents, particularly those with low contrast or complex color schemes, making them easier to read and understand.

  3. Efficient File Storage: Grayscale PDFs typically have smaller file sizes compared to their color counterparts, allowing businesses to save on storage costs and improve document management efficiency.

  4. Accessibility Compliance: Converting documents to grayscale can help businesses meet accessibility standards by improving contrast and readability for visually impaired users.

  5. Streamlined Document Processing: The automated conversion process saves time and reduces manual effort, allowing employees to focus on more value-added tasks rather than document formatting.

Technologies

Optimize PDF Workflows with Lazy AI: Automate Document Creation, Editing, Extraction and More Optimize PDF Workflows with Lazy AI: Automate Document Creation, Editing, Extraction and More

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