CamScanner Remove Image Watermark

SKILL.md

---
name: camscanner-image-remove-watermark
description: Use CamScanner to remove watermarks from images while preserving the underlying content and original layout. Powered by a high-precision image enhancement engine that intelligently detects and erases overlaid watermarks, stamps, and translucent logos, leaving the underlying document clean and legible. Use when the user wants to remove watermarks from a photo or scan, clean up stamped documents, or recover a clean copy of a watermarked image. Triggers on "remove watermark", "erase watermark from image", "delete watermark", "clean watermarked scan", "unwatermark", or when the user has an image with a watermark that needs to be removed.
metadata:
  author: CamScanner
  version: "1.0"
  openclaw:
    emoji: "💧"
    requires:
      bins: ["curl", "jq"]
  homepage: "https://www.camscanner.com"
---

# CamScanner Image Remove Watermark

## Overview

CamScanner provides a high-precision image enhancement engine that removes watermarks from images while preserving the underlying content and original layout. It intelligently detects overlaid watermarks, stamps, and translucent logos and erases them, leaving the underlying document clean and legible. The workflow is a 3-step pipeline: **upload** the image, **enhance** it with `enhance_mode: 10` (remove watermark), then **download** the result. For convenience, the enhance step also supports a `raw` output mode that returns the processed image bytes directly, skipping the download step.

## When to Use

- User wants to remove watermarks, stamps, or translucent logos from an image
- User has a scan or photo of a document with a watermark that needs to be cleaned
- User wants to recover a clean copy of a watermarked image
- User has a watermarked scan and needs a clean copy for OCR, printing, or sharing

## Privacy & Data

> **Important: Privacy & Data Flow Notice**
>
> - **Third-party service**: This skill sends your files to CamScanner's official servers (`ai-tools.camscanner.com`) for processing.
> - **Data retention**: CamScanner servers process your files in real-time. Files are not permanently stored on the server.
> - **Local files**: Output files are saved to your local filesystem at the path you specify.

## API Reference

**Base URL:** `https://ai-tools.camscanner.com`

### Supported Enhancements

| source_type | enhance_mode | Operation         | Output |
| ----------- | ------------ | ----------------- | ------ |
| image       | 10           | Remove watermark  | .jpg   |

### Step 1: Upload Image

```bash
BASE="https://ai-tools.camscanner.com"

IN_FILE_ID=$(curl -sS -X POST "$BASE/v1/tools/upload_file/execute" \
  -H "Content-Type: application/octet-stream" \
  --data-binary "@/path/to/image.jpg" | jq -r '.tool_result.data.file_id')
```

**Response:**

```json
{
  "code": 200,
  "tool": "upload_file",
  "tool_result": {
    "success": true,
    "data": {
      "file_id": "file_1741857600_ab12cd34ef56",
      "size": 24576
    }
  }
}
```

### Step 2: Enhance Image (Remove Watermark)

```bash
OUT_FILE_ID=$(curl -sS -X POST "$BASE/v1/tools/enhance_image/execute" \
  -H "Content-Type: application/json" \
  -d "{\"file_id\":\"$IN_FILE_ID\",\"enhance_mode\":10,\"output_mode\":\"file_id\"}" \
  | jq -r '.tool_result.data.file_id')
```

**Response:**

```json
{
  "code": 200,
  "tool": "enhance_image",
  "tool_result": {
    "success": true,
    "data": {
      "file_id": "file_1741857701_9988aabbccdd",
      "enhance_mode": 10
    }
  }
}
```

### Step 3: Download Result

```bash
curl -sS -X POST "$BASE/v1/tools/download_file/execute?response_mode=raw" \
  -H "Content-Type: application/json" \
  -d "{\"file_id\":\"$OUT_FILE_ID\"}" \
  -o /path/to/output.jpg
```

**Critical:** The `response_mode=raw` query parameter is required to get the binary file. Without it, the response is JSON.

### Alternative: One-Shot Raw Output

If you don't need a reusable `file_id` for the result, pass `"output_mode": "raw"` to `enhance_image` and save the response body directly — this combines steps 2 and 3:

```bash
curl -sS -X POST "$BASE/v1/tools/enhance_image/execute" \
  -H "Content-Type: application/json" \
  -d "{\"file_id\":\"$IN_FILE_ID\",\"enhance_mode\":10,\"output_mode\":\"raw\"}" \
  -o /path/to/output.jpg
```

## Quick Reference: Complete Pipeline

Remove watermark from an image (three-step, keeps an output `file_id`):

```bash
BASE="https://ai-tools.camscanner.com"
INPUT_IMAGE="/path/to/image.jpg"
OUTPUT_FILE="/path/to/output.jpg"

# Upload
IN_FILE_ID=$(curl -sS -X POST "$BASE/v1/tools/upload_file/execute" \
  -H "Content-Type: application/octet-stream" \
  --data-binary "@$INPUT_IMAGE" | jq -r '.tool_result.data.file_id')

# Enhance (remove watermark)
OUT_FILE_ID=$(curl -sS -X POST "$BASE/v1/tools/enhance_image/execute" \
  -H "Content-Type: application/json" \
  -d "{\"file_id\":\"$IN_FILE_ID\",\"enhance_mode\":10,\"output_mode\":\"file_id\"}" \
  | jq -r '.tool_result.data.file_id')

# Download
curl -sS -X POST "$BASE/v1/tools/download_file/execute?response_mode=raw" \
  -H "Content-Type: application/json" \
  -d "{\"file_id\":\"$OUT_FILE_ID\"}" \
  -o "$OUTPUT_FILE"
```

Or one-shot (two-step, raw image stream straight from `enhance_image`):

```bash
BASE="https://ai-tools.camscanner.com"
INPUT_IMAGE="/path/to/image.jpg"
OUTPUT_FILE="/path/to/output.jpg"

# Upload
IN_FILE_ID=$(curl -sS -X POST "$BASE/v1/tools/upload_file/execute" \
  -H "Content-Type: application/octet-stream" \
  --data-binary "@$INPUT_IMAGE" | jq -r '.tool_result.data.file_id')

# Enhance + download in one call
curl -sS -X POST "$BASE/v1/tools/enhance_image/execute" \
  -H "Content-Type: application/json" \
  -d "{\"file_id\":\"$IN_FILE_ID\",\"enhance_mode\":10,\"output_mode\":\"raw\"}" \
  -o "$OUTPUT_FILE"
```

## Common Mistakes

| Mistake                                             | Fix                                                                           |
| --------------------------------------------------- | ----------------------------------------------------------------------------- |
| Forgetting `response_mode=raw` on download          | Always append `?response_mode=raw` to the download URL                        |
| Wrong Content-Type on upload                        | Upload uses `application/octet-stream`, not `multipart/form-data`             |
| Using GET instead of POST                           | All endpoints use POST                                                        |
| Passing `enhance_mode` as a string                  | `enhance_mode` is an integer — use `10`, not `"10"`                           |
| Missing `output_mode` in enhance request            | Must be either `"file_id"` (then download separately) or `"raw"` (stream out) |
| Parsing JSON when `output_mode` is `"raw"`          | With `raw`, the response body IS the image — write it to a file with `-o`    |
| Trying to download a `file_id` after `raw` response | `raw` mode returns no `file_id`; re-run in `file_id` mode if you need one     |

## Error Handling

Check each step before proceeding:

```bash
# After upload
if [ -z "$IN_FILE_ID" ] || [ "$IN_FILE_ID" = "null" ]; then
  echo "Upload failed"; exit 1
fi

# After enhance (file_id mode)
if [ -z "$OUT_FILE_ID" ] || [ "$OUT_FILE_ID" = "null" ]; then
  echo "Enhancement failed"; exit 1
fi
```