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

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

Quick Start

1. Setup Baidu OCR

Get API credentials from https://cloud.baidu.com/product/ocr:

Register/login to Baidu Cloud
Create an application
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