image-format-library 1.0.0
A flexible library for custom image format encoding and decoding
License: MIT
Requires Python: >=3.7
Keywords: image, compression, format, encoding, decoding, billi

# Image Format Library

A flexible Python library for creating and handling custom image formats with support for various compression algorithms and customizable file extensions.

## Features

- **Custom Image Formats**: Create your own image formats with custom signatures and extensions
- **BILLI Format**: Built-in support for the BILLI format with JPEG compression
- **Metadata Removal**: Automatically strips all metadata from images during encoding
- **Flexible Extensions**: Use any file extension you want (`.billi`, `.myformat`, `.compressed`, etc.)
- **Batch Processing**: Process multiple images at once
- **Compression Stats**: Detailed compression statistics and ratios
- **Quality Control**: Adjustable quality settings (1-100)

## Installation

```bash
pip install image-format-library
```

## Quick Start

```python
from image_format_library import encode, decode, get_info

# Encode an image to BILLI format
stats = encode('billi', 'input.jpg', 'output.billi', quality=85)
print(f"Compression ratio: {stats['compression_ratio']:.2f}:1")

# Decode back to regular image
decode('billi', 'output.billi', 'decoded.jpg')

# Get file information
info = get_info('billi', 'output.billi')
print(f"Dimensions: {info['width']}x{info['height']}")
```

## Advanced Usage

### Using the Library Class

```python
from image_format_library import ImageFormatLibrary

# Create library with custom extension
library = ImageFormatLibrary('myformat')

# Encode with custom settings
stats = library.encode('billi', 'image.png', 'image.myformat', quality=90)

# Batch process a folder
from image_format_library import batch_encode
batch_encode('/path/to/images', format_name='billi', quality=80, extension='compressed')
```

### Custom Extensions

```python
from image_format_library import ImageFormatLibrary

# Use any extension you want
library = ImageFormatLibrary('awesome')
library.encode('billi', 'input.jpg', 'output.awesome')

# Change extension later
library.set_extension('cool')
library.encode('billi', 'input2.jpg', 'output2.cool')
```

## API Reference

### Main Functions

#### `encode(format_name, input_path, output_path, quality=85, extension='billi')`

Encode an image to the specified format.

**Parameters:**
- `format_name` (str): Format to use (currently supports 'billi')
- `input_path` (str): Path to input image
- `output_path` (str): Path for output file
- `quality` (int): Quality setting 1-100, default 85
- `extension` (str): File extension to use, default 'billi'

**Returns:**
- `dict`: Encoding statistics including compression ratio and file sizes

#### `decode(format_name, input_path, output_path, extension='billi')`

Decode a file back to a regular image.

**Parameters:**
- `format_name` (str): Format to decode (currently supports 'billi')
- `input_path` (str): Path to encoded file
- `output_path` (str): Path for decoded image
- `extension` (str): Expected file extension, default 'billi'

**Returns:**
- `dict`: Decoding information including dimensions and quality

#### `get_info(format_name, file_path, extension='billi')`

Get information about an encoded file without decoding it.

**Parameters:**
- `format_name` (str): Format of the file
- `file_path` (str): Path to the file
- `extension` (str): Expected file extension

**Returns:**
- `dict`: File information including dimensions, quality, and file size

#### `batch_encode(folder_path, format_name='billi', quality=85, extension='billi')`

Encode all supported images in a folder.

**Parameters:**
- `folder_path` (str): Path to folder containing images
- `format_name` (str): Format to use for encoding
- `quality` (int): Quality setting for encoding
- `extension` (str): File extension for output files

### ImageFormatLibrary Class

The main class for handling multiple format types and custom extensions.

```python
library = ImageFormatLibrary(custom_extension='billi')

# Available methods:
library.encode(format_name, input_path, output_path, quality=85, extension=None)
library.decode(format_name, input_path, output_path, extension=None)
library.get_info(format_name, file_path)
library.get_supported_formats()
library.set_extension(extension)
```

## Supported Input Formats

The library can encode from these image formats:
- JPEG (.jpg, .jpeg)
- PNG (.png)
- BMP (.bmp)
- TIFF (.tiff)
- WebP (.webp)

## BILLI Format Specification

The BILLI format uses a simple 18-byte header followed by JPEG-compressed image data:

```
Bytes 0-4:   Signature "BILLI"
Byte 5:      Version (1)
Bytes 6-9:   Width (32-bit unsigned int, little-endian)
Bytes 10-13: Height (32-bit unsigned int, little-endian)
Byte 14:     Quality (8-bit unsigned int)
Bytes 15-18: Data size (32-bit unsigned int, little-endian)
Bytes 19+:   JPEG image data
```

## Examples

### Basic Usage

```python
import image_format_library as ifl

# Simple encode/decode
stats = ifl.encode('billi', 'photo.jpg', 'photo.billi', quality=95)
ifl.decode('billi', 'photo.billi', 'photo_decoded.jpg')

# Check what formats are supported
formats = ifl.get_supported_formats()
print(f"Supported formats: {formats}")
```

### Batch Processing

```python
from image_format_library import batch_encode

# Process all images in a directory
batch_encode(
    folder_path='/path/to/photos',
    format_name='billi',
    quality=85,
    extension='compressed'
)
```

### Custom File Extensions

```python
from image_format_library import ImageFormatLibrary

# Create library with custom extension
lib = ImageFormatLibrary('myext')

# All operations will use .myext extension
lib.encode('billi', 'input.jpg', 'output')  # Creates output.myext
lib.decode('billi', 'output.myext', 'decoded.jpg')

# Change extension on the fly
lib.set_extension('data')
lib.encode('billi', 'input2.jpg', 'output2')  # Creates output2.data
```

## Error Handling

The library provides clear error messages for common issues:

```python
try:
    ifl.encode('billi', 'nonexistent.jpg', 'output.billi')
except FileNotFoundError:
    print("Input file not found")

try:
    ifl.decode('billi', 'corrupted.billi', 'output.jpg')
except ValueError as e:
    print(f"Invalid file format: {e}")
```

## Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

## License

This project is licensed under the MIT License - see the LICENSE file for details.

## Changelog

### Version 1.0.0
- Initial release
- BILLI format support
- Custom file extensions
- Batch processing
- Comprehensive API

## Requirements

- Python ≥ 3.7
- Pillow ≥ 8.0.0

## Support

If you encounter any issues or have questions, please file an issue on the GitHub repository.