invoice-extractor

# Invoice Extractor

Extract invoice information from images (PNG, JPG) and PDF files, then export to Excel format.

## Capabilities

- **Multi-format support**: PNG, JPG, JPEG, BMP, TIFF, PDF
- **High accuracy**: Uses Baidu OCR API specialized for invoice recognition
- **Complete fields**: Extracts all invoice fields including buyer/seller info, amounts, items
- **Excel export**: Formatted Excel output with summary and detail sheets
- **Flexible input**: Single file, multiple files, or entire directory processing
- **Batch processing**: Process hundreds of invoices in one command
- **Preview mode**: List files before processing

## Prerequisites

1. Baidu Cloud OCR API credentials (free tier: 50,000 requests/day)
2. Python environment with required packages

## Quick Start

### 1. Setup Baidu OCR

Get API credentials from https://cloud.baidu.com/product/ocr:
1. Register/login to Baidu Cloud
2. Create an application
3. Get API Key and Secret Key

### 2. Configure

Create `config.txt` in the project root:
```
BAIDU_API_KEY=your_api_key_here
BAIDU_SECRET_KEY=your_secret_key_here
```

Or run the setup wizard:
```bash
python main_baidu.py --setup
```

### 3. Run

**Process a single file:**
```bash
python main_baidu.py -f invoice.pdf
```

**Process multiple files:**
```bash
python main_baidu.py -f invoice1.pdf -f invoice2.png
```

**Process entire directory:**
```bash
python main_baidu.py -i ./fp
```

**Mixed mode (directory + extra files):**
```bash
python main_baidu.py -i ./fp -f extra_invoice.pdf
```

Output will be saved to `output/` directory as Excel file.

## Workflow

```
Task Progress:
- [ ] Check prerequisites (Baidu API credentials)
- [ ] Choose input method (single file / multiple files / directory)
- [ ] Scan and collect invoice files
- [ ] Preview files (optional with --list)
- [ ] Process each file with Baidu OCR
- [ ] Parse invoice fields
- [ ] Export to Excel
- [ ] Verify output
```

## Input Methods

### Single File
Process one specific invoice file:
```bash
python main_baidu.py -f invoice.pdf
python main_baidu.py -f "path/to/invoice.png"
```

### Multiple Files
Process several specific files:
```bash
python main_baidu.py -f file1.pdf -f file2.png -f file3.jpg
```

### Entire Directory
Process all invoice files in a directory (recursive):
```bash
python main_baidu.py -i ./my_invoices
python main_baidu.py -i "/path/to/invoice/folder"
```

### Mixed Mode
Combine directory and individual files:
```bash
python main_baidu.py -i ./fp -f ./extra/invoice.pdf
```

### Preview Mode
List files without processing:
```bash
python main_baidu.py -i ./fp --list
```

## Extracted Fields

### Basic Information
- Invoice code (发票代码)
- Invoice number (发票号码)
- Invoice date (开票日期)
- Invoice type (发票类型)

### Buyer Information
- Name (购买方名称)
- Tax number (纳税人识别号)
- Address and phone (地址电话)
- Bank account (开户行及账号)

### Seller Information
- Name (销售方名称)
- Tax number (纳税人识别号)
- Address and phone (地址电话)
- Bank account (开户行及账号)

### Amounts
- Total amount (合计金额)
- Total tax (合计税额)
- Amount with tax (价税合计)

### Items
- Product name (货物名称)
- Specification (规格型号)
- Unit (单位)
- Quantity (数量)
- Unit price (单价)
- Amount (金额)
- Tax rate (税率)
- Tax amount (税额)

## Command Line Options

```bash
python main_baidu.py [options]

Input Options:
  -f FILE, --file FILE     Specify invoice file (can be used multiple times)
  -i DIR, --input DIR      Input directory (default: fp)

Output Options:
  -o DIR, --output DIR     Output directory (default: output)
  -n NAME, --name NAME     Output filename prefix (default: 发票信息)

Authentication Options:
  --api-key KEY            Baidu API Key
  --secret-key KEY         Baidu Secret Key

Other Options:
  --setup                  Run configuration wizard
  --list                   List files to be processed without processing
  -h, --help              Show help
```

## Usage Examples

### Example 1: Single File
```bash
python main_baidu.py -f "invoice.pdf"
```

### Example 2: Multiple Files
```bash
python main_baidu.py -f "1.pdf" -f "2.png" -f "3.jpg"
```

### Example 3: Entire Directory
```bash
python main_baidu.py -i "./2024_invoices"
```

### Example 4: Preview Before Processing
```bash
python main_baidu.py -i ./fp --list
# Then process:
python main_baidu.py -i ./fp
```

### Example 5: Mixed Input
```bash
python main_baidu.py -i ./fp -f ./urgent/invoice.pdf -o ./output -n "March_2024"
```

### Example 6: Custom Output
```bash
python main_baidu.py -i ./fp -o ./reports -n "Q1_Invoice_Summary"
```

## Project Structure

```
.
├── fp/                      # Place invoice files here
├── output/                  # Excel output directory
├── src/
│   ├── main_baidu.py       # Main entry point
│   ├── baidu_ocr_extractor.py  # Baidu OCR wrapper
│   ├── invoice_model.py    # Data models
│   ├── excel_exporter.py   # Excel export
│   └── config.py           # Configuration
├── scripts/                 # Utility scripts
│   ├── batch_process.py    # Batch processing helper
│   └── verify_export.py    # Verify Excel export
├── config.txt              # API credentials
├── requirements.txt        # Dependencies
├── SKILL.md                # This file
├── setup.md                # Detailed setup guide
└── examples.md             # Usage examples
```

## Utility Scripts

### Batch Processing Helper
```bash
python scripts/batch_process.py /path/to/invoices
```

### Verify Export
```bash
python scripts/verify_export.py output/invoice_info.xlsx
```

## Error Handling

Common issues and solutions:

**"Baidu OCR authentication failed"**
- Check API Key and Secret Key in config.txt
- Verify credentials are correct in Baidu Cloud console

**"No invoice files found"**
- Ensure files are in the specified directory
- Check file formats (supported: png, jpg, jpeg, bmp, tiff, pdf)
- Use `--list` to see what files are detected

**"Image format error"**
- PDF files are automatically converted to images
- Ensure PDF is not corrupted or password-protected

**"File not found"**
- Check file path is correct
- Use quotes for paths with spaces: `"path/to/file name.pdf"`

## Advanced Usage

### Environment Variables
Set credentials via environment:
```bash
export BAIDU_API_KEY="your_key"
export BAIDU_SECRET_KEY="your_secret"
```

### Batch Processing Script
Create a script for monthly processing:
```bash
#!/bin/bash
MONTH=$(date +%Y%m)
python main_baidu.py \
  -i "/invoices/$MONTH" \
  -o "/reports/$MONTH" \
  -n "Invoice_Report_$MONTH"
```

## Additional Resources

- For detailed setup instructions, see [setup.md](setup.md)
- For more examples, see [examples.md](examples.md)
- For API documentation, visit https://cloud.baidu.com/doc/OCR/index.html