PDF to Image Conversion Service Documentation

This service provides functionality to convert PDF pages to images, serve these images with various transformations, and generate responsive image HTML.

Endpoints

1. Convert PDF to Image

Endpoint: /convert Method: POST

Convert a page from a PDF file to an image.

Parameters:

file: The PDF file (multipart/form-data)
page: Page number to convert (default: 1)

Response:

{
	"id": "unique_filename",
	"original_filename": "uploaded_file.pdf",
	"page": 1,
	"url": "http://server-address:5000/image/unique_filename"
}

2. Serve Image

Endpoint: /image/<filename> Method: GET

Serve an image with optional transformations.

Query Parameters:

format: Image format (default: webp)
width: Resize width
height: Resize height
crop_width: Width to crop the image
crop_height: Height to crop the image
focus_x: Horizontal focus point for cropping (0 to 1, default: 0.5)
focus_y: Vertical focus point for cropping (0 to 1, default: 0.5)

Example:

/image/abc123?format=jpg&width=800&height=600&crop_width=500&crop_height=300&focus_x=0.3&focus_y=0.7

3. Responsive Image HTML

Endpoint: /responsive/<filename> Method: GET

Generate HTML for a responsive image tag.

Query Parameters:

crop_width: Width to crop the image
crop_height: Height to crop the image
focus_x: Horizontal focus point for cropping (0 to 1, default: 0.5)
focus_y: Vertical focus point for cropping (0 to 1, default: 0.5)

Example:

/responsive/abc123?crop_width=800&crop_height=600&focus_x=0.3&focus_y=0.2

Response: HTML string with <img> tag including srcset and sizes attributes.

Features

PDF Conversion: Convert specific pages of PDF files to images.
Image Resizing: Resize images to specified dimensions.
Format Conversion: Convert images to different formats (e.g., WebP, JPEG, PNG).
Image Cropping: Crop images to specified dimensions with adjustable focus points.
Responsive Images: Generate HTML for responsive images with appropriate srcset and sizes attributes.
Caching: Redis-based caching for improved performance.

Usage Examples

Convert a PDF page to an image:

curl -X POST -F "file=@document.pdf" -F "page=1" http://server-address:5000/convert

Serve a resized and cropped image:

http://server-address:5000/image/abc123?width=800&height=600&crop_width=500&crop_height=300&focus_x=0.3&focus_y=0.7&format=webp

Get responsive image HTML:

http://server-address:5000/responsive/abc123?crop_width=800&crop_height=600&focus_x=0.3&focus_y=0.2

Notes

The service uses WebP as the default image format for better compression and faster loading times.
Responsive images are generated with breakpoints at 320px, 480px, 640px, 768px, 1024px, 1280px, and 1536px widths.
Images are cached in Redis for 24 hours to improve performance for repeated requests.
The service uses lazy loading for responsive images to optimize page load times.

For any issues or feature requests, please contact the development team.

abteilung/pdf2img