Python Bindings for fpng

Implemets Python interface to call fpng functions. fpng is a super fast C++ .PNG writer/reader.

Note that the images written / read are in RGB channel order, in contrast to OpenCV that reads / writes files in BGR format.

Installation

1. Clone repository git clone --recurse-submodules git@github.com:qrmt/fpng-python.git
2. Install python setup.py install

Usage

import pyfpng      # Calls fpng::init() on import

# Encode numpy array and write to file:
data = np.zeros((512, 512, 3), dtype=np.uint8)
success: bool = pyfpng.encode_image_to_file('sample.png', data)

# Encode numpy array to memory
success: bool
encoded: Optional[bytes]
success, encoded = pyfpng.encode_image_to_memory(data)

# Decode file to memory
success: int # see fpng.h
data: Optional[NDArray[np.uint8]]
success, data = pyfpng.decode_file_to_memory('sample.png')

# Decode bytes to memory
with open('sample.png', 'rb') as f:
    bytes_data = f.read()

success, data = pyfpng.decode_to_memory(bytes_data)

# Get info about file (e.g. if it can be decoded using pyfpng)
ret, height, width, channels = pyfpng.get_info(bytes_data)
if ret == 0:
    # can decode...
    ...
else:
    # see fpng.h for details on error code
    ...

Performance

In tests, beats cv2.imwrite / cv2.imencode by ~5x, with similar result file size. For cv2.imread/cv2.imdecode, ~10-20% faster.

License

Licensed under Unlicense