266 lines
8.3 KiB
Python
266 lines
8.3 KiB
Python
# A binary morphology add-on for the Python Imaging Library
|
|
#
|
|
# History:
|
|
# 2014-06-04 Initial version.
|
|
#
|
|
# Copyright (c) 2014 Dov Grobgeld <dov.grobgeld@gmail.com>
|
|
from __future__ import annotations
|
|
|
|
import re
|
|
|
|
from . import Image, _imagingmorph
|
|
|
|
LUT_SIZE = 1 << 9
|
|
|
|
# fmt: off
|
|
ROTATION_MATRIX = [
|
|
6, 3, 0,
|
|
7, 4, 1,
|
|
8, 5, 2,
|
|
]
|
|
MIRROR_MATRIX = [
|
|
2, 1, 0,
|
|
5, 4, 3,
|
|
8, 7, 6,
|
|
]
|
|
# fmt: on
|
|
|
|
|
|
class LutBuilder:
|
|
"""A class for building a MorphLut from a descriptive language
|
|
|
|
The input patterns is a list of a strings sequences like these::
|
|
|
|
4:(...
|
|
.1.
|
|
111)->1
|
|
|
|
(whitespaces including linebreaks are ignored). The option 4
|
|
describes a series of symmetry operations (in this case a
|
|
4-rotation), the pattern is described by:
|
|
|
|
- . or X - Ignore
|
|
- 1 - Pixel is on
|
|
- 0 - Pixel is off
|
|
|
|
The result of the operation is described after "->" string.
|
|
|
|
The default is to return the current pixel value, which is
|
|
returned if no other match is found.
|
|
|
|
Operations:
|
|
|
|
- 4 - 4 way rotation
|
|
- N - Negate
|
|
- 1 - Dummy op for no other operation (an op must always be given)
|
|
- M - Mirroring
|
|
|
|
Example::
|
|
|
|
lb = LutBuilder(patterns = ["4:(... .1. 111)->1"])
|
|
lut = lb.build_lut()
|
|
|
|
"""
|
|
|
|
def __init__(
|
|
self, patterns: list[str] | None = None, op_name: str | None = None
|
|
) -> None:
|
|
if patterns is not None:
|
|
self.patterns = patterns
|
|
else:
|
|
self.patterns = []
|
|
self.lut: bytearray | None = None
|
|
if op_name is not None:
|
|
known_patterns = {
|
|
"corner": ["1:(... ... ...)->0", "4:(00. 01. ...)->1"],
|
|
"dilation4": ["4:(... .0. .1.)->1"],
|
|
"dilation8": ["4:(... .0. .1.)->1", "4:(... .0. ..1)->1"],
|
|
"erosion4": ["4:(... .1. .0.)->0"],
|
|
"erosion8": ["4:(... .1. .0.)->0", "4:(... .1. ..0)->0"],
|
|
"edge": [
|
|
"1:(... ... ...)->0",
|
|
"4:(.0. .1. ...)->1",
|
|
"4:(01. .1. ...)->1",
|
|
],
|
|
}
|
|
if op_name not in known_patterns:
|
|
msg = "Unknown pattern " + op_name + "!"
|
|
raise Exception(msg)
|
|
|
|
self.patterns = known_patterns[op_name]
|
|
|
|
def add_patterns(self, patterns: list[str]) -> None:
|
|
self.patterns += patterns
|
|
|
|
def build_default_lut(self) -> None:
|
|
symbols = [0, 1]
|
|
m = 1 << 4 # pos of current pixel
|
|
self.lut = bytearray(symbols[(i & m) > 0] for i in range(LUT_SIZE))
|
|
|
|
def get_lut(self) -> bytearray | None:
|
|
return self.lut
|
|
|
|
def _string_permute(self, pattern: str, permutation: list[int]) -> str:
|
|
"""string_permute takes a pattern and a permutation and returns the
|
|
string permuted according to the permutation list.
|
|
"""
|
|
assert len(permutation) == 9
|
|
return "".join(pattern[p] for p in permutation)
|
|
|
|
def _pattern_permute(
|
|
self, basic_pattern: str, options: str, basic_result: int
|
|
) -> list[tuple[str, int]]:
|
|
"""pattern_permute takes a basic pattern and its result and clones
|
|
the pattern according to the modifications described in the $options
|
|
parameter. It returns a list of all cloned patterns."""
|
|
patterns = [(basic_pattern, basic_result)]
|
|
|
|
# rotations
|
|
if "4" in options:
|
|
res = patterns[-1][1]
|
|
for i in range(4):
|
|
patterns.append(
|
|
(self._string_permute(patterns[-1][0], ROTATION_MATRIX), res)
|
|
)
|
|
# mirror
|
|
if "M" in options:
|
|
n = len(patterns)
|
|
for pattern, res in patterns[:n]:
|
|
patterns.append((self._string_permute(pattern, MIRROR_MATRIX), res))
|
|
|
|
# negate
|
|
if "N" in options:
|
|
n = len(patterns)
|
|
for pattern, res in patterns[:n]:
|
|
# Swap 0 and 1
|
|
pattern = pattern.replace("0", "Z").replace("1", "0").replace("Z", "1")
|
|
res = 1 - int(res)
|
|
patterns.append((pattern, res))
|
|
|
|
return patterns
|
|
|
|
def build_lut(self) -> bytearray:
|
|
"""Compile all patterns into a morphology lut.
|
|
|
|
TBD :Build based on (file) morphlut:modify_lut
|
|
"""
|
|
self.build_default_lut()
|
|
assert self.lut is not None
|
|
patterns = []
|
|
|
|
# Parse and create symmetries of the patterns strings
|
|
for p in self.patterns:
|
|
m = re.search(r"(\w*):?\s*\((.+?)\)\s*->\s*(\d)", p.replace("\n", ""))
|
|
if not m:
|
|
msg = 'Syntax error in pattern "' + p + '"'
|
|
raise Exception(msg)
|
|
options = m.group(1)
|
|
pattern = m.group(2)
|
|
result = int(m.group(3))
|
|
|
|
# Get rid of spaces
|
|
pattern = pattern.replace(" ", "").replace("\n", "")
|
|
|
|
patterns += self._pattern_permute(pattern, options, result)
|
|
|
|
# compile the patterns into regular expressions for speed
|
|
compiled_patterns = []
|
|
for pattern in patterns:
|
|
p = pattern[0].replace(".", "X").replace("X", "[01]")
|
|
compiled_patterns.append((re.compile(p), pattern[1]))
|
|
|
|
# Step through table and find patterns that match.
|
|
# Note that all the patterns are searched. The last one
|
|
# caught overrides
|
|
for i in range(LUT_SIZE):
|
|
# Build the bit pattern
|
|
bitpattern = bin(i)[2:]
|
|
bitpattern = ("0" * (9 - len(bitpattern)) + bitpattern)[::-1]
|
|
|
|
for pattern, r in compiled_patterns:
|
|
if pattern.match(bitpattern):
|
|
self.lut[i] = [0, 1][r]
|
|
|
|
return self.lut
|
|
|
|
|
|
class MorphOp:
|
|
"""A class for binary morphological operators"""
|
|
|
|
def __init__(
|
|
self,
|
|
lut: bytearray | None = None,
|
|
op_name: str | None = None,
|
|
patterns: list[str] | None = None,
|
|
) -> None:
|
|
"""Create a binary morphological operator"""
|
|
self.lut = lut
|
|
if op_name is not None:
|
|
self.lut = LutBuilder(op_name=op_name).build_lut()
|
|
elif patterns is not None:
|
|
self.lut = LutBuilder(patterns=patterns).build_lut()
|
|
|
|
def apply(self, image: Image.Image):
|
|
"""Run a single morphological operation on an image
|
|
|
|
Returns a tuple of the number of changed pixels and the
|
|
morphed image"""
|
|
if self.lut is None:
|
|
msg = "No operator loaded"
|
|
raise Exception(msg)
|
|
|
|
if image.mode != "L":
|
|
msg = "Image mode must be L"
|
|
raise ValueError(msg)
|
|
outimage = Image.new(image.mode, image.size, None)
|
|
count = _imagingmorph.apply(bytes(self.lut), image.im.id, outimage.im.id)
|
|
return count, outimage
|
|
|
|
def match(self, image: Image.Image):
|
|
"""Get a list of coordinates matching the morphological operation on
|
|
an image.
|
|
|
|
Returns a list of tuples of (x,y) coordinates
|
|
of all matching pixels. See :ref:`coordinate-system`."""
|
|
if self.lut is None:
|
|
msg = "No operator loaded"
|
|
raise Exception(msg)
|
|
|
|
if image.mode != "L":
|
|
msg = "Image mode must be L"
|
|
raise ValueError(msg)
|
|
return _imagingmorph.match(bytes(self.lut), image.im.id)
|
|
|
|
def get_on_pixels(self, image: Image.Image):
|
|
"""Get a list of all turned on pixels in a binary image
|
|
|
|
Returns a list of tuples of (x,y) coordinates
|
|
of all matching pixels. See :ref:`coordinate-system`."""
|
|
|
|
if image.mode != "L":
|
|
msg = "Image mode must be L"
|
|
raise ValueError(msg)
|
|
return _imagingmorph.get_on_pixels(image.im.id)
|
|
|
|
def load_lut(self, filename: str) -> None:
|
|
"""Load an operator from an mrl file"""
|
|
with open(filename, "rb") as f:
|
|
self.lut = bytearray(f.read())
|
|
|
|
if len(self.lut) != LUT_SIZE:
|
|
self.lut = None
|
|
msg = "Wrong size operator file!"
|
|
raise Exception(msg)
|
|
|
|
def save_lut(self, filename: str) -> None:
|
|
"""Save an operator to an mrl file"""
|
|
if self.lut is None:
|
|
msg = "No operator loaded"
|
|
raise Exception(msg)
|
|
with open(filename, "wb") as f:
|
|
f.write(self.lut)
|
|
|
|
def set_lut(self, lut: bytearray | None) -> None:
|
|
"""Set the lut from an external source"""
|
|
self.lut = lut
|