PaperClean

About PaperClean

PaperClean is an API for cleaning up and enhancing document images, aimed at use cases such as scanned documents, photos of papers, and whiteboards. It exposes REST endpoints for full document cleanup with a configurable two-pass enhancement process, perspective-correction cropping using four corner coordinates, and a combined pipeline endpoint that can perform cropping and enhancement in a single request. Image processing parameters such as number of passes, detail level (scales), gamma correction, and black/white point levels can be adjusted per request. Accepted image formats are JPG, PNG, WebP, and TIFF, with a maximum file size of 32MB; processed images are returned directly as image/jpeg.

Authentication is done via an X-API-Key header or an api_key query parameter, and API keys can be obtained through a registration endpoint that requires only an email address. The API also provides a usage endpoint to check current plan, monthly image limit, images used, and remaining quota, and returns rate limit information in response headers. It is intended for developers building applications that need programmatic document scanning, cleanup, or perspective correction functionality.

The service is offered on tiered plans based on monthly image volume: a Free plan with 50 images/month, a Starter plan (500 images/month), a Pro plan (5,000 images/month), and an Enterprise plan with unlimited images. Starter and Pro plans are listed with both standard and launch pricing. Example usage is documented for curl, Python, and Node.js, and errors are returned as JSON with standard HTTP status codes for cases such as invalid API keys, inactive keys, rate limit exhaustion, and processing failures.

Key features

• Two-pass document image cleanup and enhancement
• Perspective correction cropping via four corner coordinates
• Configurable pipeline combining crop and enhancement in one request
• Adjustable gamma, black point, and white point correction
• Usage tracking endpoint for checking plan limits
• Free API key registration with no authentication required

Frequently asked questions