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:

python main_baidu.py --setup

3. Run

Process a single file:

python main_baidu.py -f invoice.pdf

Process multiple files:

python main_baidu.py -f invoice1.pdf -f invoice2.png

Process entire directory:

python main_baidu.py -i ./fp

Mixed mode (directory + extra files):

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:

python main_baidu.py -f invoice.pdf
python main_baidu.py -f "path/to/invoice.png"

Multiple Files

Process several specific files:

python main_baidu.py -f file1.pdf -f file2.png -f file3.jpg

Entire Directory

Process all invoice files in a directory (recursive):

python main_baidu.py -i ./my_invoices
python main_baidu.py -i "/path/to/invoice/folder"

Mixed Mode

Combine directory and individual files:

python main_baidu.py -i ./fp -f ./extra/invoice.pdf

Preview Mode

List files without processing:

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

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

python main_baidu.py -f "invoice.pdf"

Example 2: Multiple Files

python main_baidu.py -f "1.pdf" -f "2.png" -f "3.jpg"

Example 3: Entire Directory

python main_baidu.py -i "./2024_invoices"

Example 4: Preview Before Processing

python main_baidu.py -i ./fp --list
# Then process:
python main_baidu.py -i ./fp

Example 5: Mixed Input

python main_baidu.py -i ./fp -f ./urgent/invoice.pdf -o ./output -n "March_2024"

Example 6: Custom Output

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

python scripts/batch_process.py /path/to/invoices

Verify Export

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:

export BAIDU_API_KEY="your_key"
export BAIDU_SECRET_KEY="your_secret"

Batch Processing Script

Create a script for monthly processing:

#!/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
• For more examples, see examples.md
• For API documentation, visit https://cloud.baidu.com/doc/OCR/index.html