How to Convert PDF Files from Color to Black and White (Grayscale) with cURL, Tutorial

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Why Convert PDFs from Color to Black and White with cURL?

The pdfRest Convert PDF Colors API Tool is a powerful feature that allows users to change the color profile of a PDF document. This tutorial will guide you through the process of sending an API call to convert a color PDF to grayscale using cURL, a command-line tool for transferring data with URLs. By following this tutorial, you'll learn how to interact with the pdfRest API to modify PDF color settings efficiently.

In a real-world scenario, a user might need to convert a PDF to black and white for various reasons, such as reducing file size, improving readability on certain devices, or preparing documents for printing. For instance, a document preparation specialist might need to convert a colorful PDF report into a grayscale version for archival purposes or to reduce printing costs. This tool provides a seamless way to make these adjustments programmatically.

Convert PDFs from Color to Black and White with cURL Code Example

curl -X POST "https://api.pdfrest.com/pdf-with-converted-colors" \
  -H "Accept: application/json" \
  -H "Content-Type: multipart/form-data" \
  -H "Api-Key: xxxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" \
  -F "file=@/path/to/file" \
  -F "output=example_out" \
  -F "color_profile=gamma-22"

Source: GitHub Repository

Breaking Down the Code

Let's take a closer look at each part of the code:

curl -X POST "https://api.pdfrest.com/pdf-with-converted-colors"

This line initiates a POST request to the pdfRest API endpoint for converting PDF colors. The -X POST flag specifies the request method.

-H "Accept: application/json"

This header tells the server that the client expects the response in JSON format, which is a common format for API responses.

-H "Content-Type: multipart/form-data"

This header specifies that the request body will be sent as multipart/form-data, which is necessary when uploading files.

-H "Api-Key: xxxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"

The Api-Key header is used for authentication. Replace xxxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx with your actual API key, which you can obtain from your pdfRest account.

-F "file=@/path/to/file"

This form field uploads the PDF file you want to convert. Replace /path/to/file with the actual path to your PDF document.

-F "output=example_out"

This field specifies the name of the output file. You can change example_out to your desired output filename.

-F "color_profile=gamma-22"

This field sets the target color profile for the conversion. In this example, the colors are being converted to the gamma-22 profile.

Beyond the Tutorial

In this tutorial, you learned how to use cURL to send an API request to the pdfRest Convert PDF Colors endpoint. This process allows you to programmatically adjust the color profile of PDF documents to meet specific requirements, like converting color to black and white. To explore more features, consider trying out all the pdfRest API Tools in the API Lab.

For more detailed information, refer to the API Reference Guide. This example demonstrates a multipart API call, and you can find code samples using JSON payloads at this GitHub repository.