"""Abstract backend interface for slide reading."""
from abc import ABC, abstractmethod
from pathlib import Path
from types import TracebackType
import PIL.Image
[docs]
class SlideBackend(ABC):
"""Abstract base class for slide reading backends.
This defines the interface that all slide backends must implement.
Backends handle the actual reading of slide files and tile extraction.
"""
[docs]
@abstractmethod
def open(self, path: str | Path) -> None:
"""Open a slide file.
Parameters
----------
path : str | Path
Path to the slide file
"""
pass
[docs]
@abstractmethod
def close(self) -> None:
"""Close the slide and free resources."""
pass
@property
@abstractmethod
def dimensions(self) -> tuple[int, int]:
"""Get slide dimensions at level 0 (width, height).
Returns
-------
tuple[int, int]
Width and height in pixels at highest magnification
"""
pass
@property
@abstractmethod
def properties(self) -> dict[str, str]:
"""Get slide metadata/properties.
Returns
-------
dict[str, str]
Dictionary of slide properties
"""
pass
@property
@abstractmethod
def num_levels(self) -> int:
"""Get number of pyramid levels.
Returns
-------
int
Number of pyramid levels
"""
pass
[docs]
@abstractmethod
def read_region(
self, location: tuple[int, int], level: int, size: tuple[int, int]
) -> PIL.Image.Image:
"""Read a region/tile from the slide.
Parameters
----------
location : tuple[int, int]
(x, y) coordinates at level 0
level : int
Pyramid level to read from
size : tuple[int, int]
(width, height) of the tile to read in pixels
Returns
-------
PIL.Image.Image
The tile image in RGB format
"""
pass
[docs]
@abstractmethod
def get_thumbnail(self, size: tuple[int, int]) -> PIL.Image.Image:
"""Get thumbnail of the slide.
Parameters
----------
size : tuple[int, int]
Maximum size of the thumbnail (width, height)
Returns
-------
PIL.Image.Image
Thumbnail image
"""
pass
@property
@abstractmethod
def mpp(self) -> float:
"""Get microns per pixel at base magnification.
Returns
-------
float
Microns per pixel
Raises
------
SlidePropertyError
If MPP cannot be determined from slide metadata
"""
pass
@property
@abstractmethod
def base_magnification(self) -> int | float:
"""Get the base magnification (objective power) of the slide.
This is the magnification at level 0 (highest resolution).
For example, 40x, 20x, 10x, etc.
Returns
-------
int | float
Base magnification value
Raises
------
SlidePropertyError
If base magnification cannot be determined from slide metadata
"""
pass
[docs]
def __enter__(self):
"""Context manager entry."""
return self
[docs]
def __exit__(
self,
exc_type: type[BaseException] | None,
exc_val: BaseException | None,
exc_tb: TracebackType | None,
) -> None:
"""Context manager exit."""
self.close()
GlassCut