# Scan Enhance — yeezhan.com
> One-time pay-per-task emergency tool to make your file ready for submission.
> No credits, no balance. One payment unlocks one task result, valid for 24 hours.

Tool domain: https://scan-enhance.yeezhan.com
Skill definition: https://scan-enhance.yeezhan.com/skill/SKILL.md
API documentation: https://scan-enhance.yeezhan.com/api/docs

## What this tool does
Clean up a scanned PDF or image: stretch the contrast, kill speckles and push the grey background back to white.

## Typical user problems
- Scans come in grey: show-through from the reverse side, dust speckles, muddy shadows where the page curved. Contrast stretching, a median filter and a white-point clamp pull the paper back to white and the ink to crisp black.

## Parameters
- strength: number (range 1-10), optional. 增强强度. 1=轻度 10=强力（映射对比拉伸上限与白化力度），越界自动钳制

## Pricing
- Watermarked preview: free, no login required
- Final clean output: $0.99 one-time per task
- Require login (email/phone OTP) to complete payment
- Result available for download 24 hours after payment

## Limitations
- PDF input is re-rendered to images (text layer lost)
- Median filter may soften 1px hairlines at high strength
- Strength is clamped to 1–10