"""PIL filter dispatch helpers."""
from typing import Any
from PIL import ImageFilter
FILTER_DICT: dict[str, Any] = {
'NONE': None,
'BLUR': ImageFilter.BLUR,
'CONTOUR': ImageFilter.CONTOUR,
'DETAIL': ImageFilter.DETAIL,
'EDGE_ENHANCE': ImageFilter.EDGE_ENHANCE,
'EDGE_ENHANCE_MORE': ImageFilter.EDGE_ENHANCE_MORE,
'EMBOSS': ImageFilter.EMBOSS,
'FIND_EDGES': ImageFilter.FIND_EDGES,
'SMOOTH': ImageFilter.SMOOTH,
'SMOOTH_MORE': ImageFilter.SMOOTH_MORE,
'SHARPEN': ImageFilter.SHARPEN,
'MEDIAN_3': ImageFilter.MedianFilter(3),
'MEDIAN_5': ImageFilter.MedianFilter(5),
'MEDIAN_7': ImageFilter.MedianFilter(7),
'MINIMUM_3': ImageFilter.MinFilter(3),
'MINIMUM_5': ImageFilter.MinFilter(5),
'MINIMUM_7': ImageFilter.MinFilter(7),
'MAXIMUM_3': ImageFilter.MaxFilter(3),
'MAXIMUM_5': ImageFilter.MaxFilter(5),
'MAXIMUM_7': ImageFilter.MaxFilter(7),
}
[docs]
def filter_image(image: Any, filter_name: str) -> Any:
"""Apply an arbitrary filter to a PIL image.
Two-byte (16-bit) images are not supported and raise ``ValueError``.
Parameters:
image: A PIL image as 8-bit RGB or grayscale.
filter_name: Name of the filter to be applied. Valid choices are the
keys of ``FILTER_DICT`` (case-insensitive). ``'NONE'`` returns
the input image unchanged.
Returns:
The filtered PIL image. For ``filter_name='NONE'`` the input
image is returned unchanged.
Raises:
ValueError: If ``image`` is a list (16-bit two-byte image).
KeyError: If ``filter_name`` (case-folded) is not a key of
:data:`picmaker._filters.FILTER_DICT`.
"""
if isinstance(image, list):
raise ValueError('filtering of 2-byte images is not supported')
filter_method = FILTER_DICT[filter_name.upper()]
if filter_method:
image = image.filter(filter_method)
return image
__all__ = ['FILTER_DICT', 'filter_image']