112 lines
3.1 KiB
Python
112 lines
3.1 KiB
Python
|
"""
|
||
|
|
raster.py
|
||
|
|
------------
|
||
|
|
|
||
|
|
Turn 2D vector paths into raster images using `pillow`
|
||
|
|
"""
|
||
|
|
import numpy as np
|
||
|
|
|
||
|
|
try:
|
||
|
|
# keep pillow as a soft dependency
|
||
|
|
from PIL import (Image,
|
||
|
|
ImageDraw,
|
||
|
|
ImageChops)
|
||
|
|
except BaseException as E:
|
||
|
|
from .. import exceptions
|
||
|
|
# re-raise the useful exception when called
|
||
|
|
closure = exceptions.closure(E)
|
||
|
|
Image = closure
|
||
|
|
ImageDraw = closure
|
||
|
|
ImageChops = closure
|
||
|
|
|
||
|
|
|
||
|
|
def rasterize(path,
|
||
|
|
pitch,
|
||
|
|
origin,
|
||
|
|
resolution=None,
|
||
|
|
fill=True,
|
||
|
|
width=None):
|
||
|
|
"""
|
||
|
|
Rasterize a Path2D object into a boolean image ("mode 1").
|
||
|
|
|
||
|
|
Parameters
|
||
|
|
------------
|
||
|
|
path : Path2D
|
||
|
|
Original geometry
|
||
|
|
pitch : float
|
||
|
|
Length in model space of a pixel edge
|
||
|
|
origin : (2,) float
|
||
|
|
Origin position in model space
|
||
|
|
resolution : (2,) int
|
||
|
|
Resolution in pixel space
|
||
|
|
fill : bool
|
||
|
|
If True will return closed regions as filled
|
||
|
|
width : int
|
||
|
|
If not None will draw outline this wide in pixels
|
||
|
|
|
||
|
|
Returns
|
||
|
|
------------
|
||
|
|
raster : PIL.Image object mode 1
|
||
|
|
Rasterized version of input
|
||
|
|
"""
|
||
|
|
|
||
|
|
# check inputs
|
||
|
|
pitch = float(pitch)
|
||
|
|
origin = np.asanyarray(origin, dtype=np.float64)
|
||
|
|
|
||
|
|
# if resolution is None make it larger than path
|
||
|
|
if resolution is None:
|
||
|
|
span = np.vstack((path.bounds,
|
||
|
|
origin)).ptp(
|
||
|
|
axis=0)
|
||
|
|
resolution = np.ceil(span / pitch) + 2
|
||
|
|
resolution = np.asanyarray(resolution,
|
||
|
|
dtype=np.int64)
|
||
|
|
resolution = tuple(resolution.tolist())
|
||
|
|
|
||
|
|
# convert all discrete paths to pixel space
|
||
|
|
discrete = [((i - origin) / pitch).astype(np.int)
|
||
|
|
for i in path.discrete]
|
||
|
|
|
||
|
|
# the path indexes that are exteriors
|
||
|
|
# needed to know what to fill/empty but expensive
|
||
|
|
roots = path.root
|
||
|
|
|
||
|
|
# draw the exteriors
|
||
|
|
exteriors = Image.new(mode='1', size=resolution)
|
||
|
|
edraw = ImageDraw.Draw(exteriors)
|
||
|
|
|
||
|
|
# if a width is specified draw the outline
|
||
|
|
if width is not None:
|
||
|
|
width = int(width)
|
||
|
|
for coords in discrete:
|
||
|
|
edraw.line(coords.flatten().tolist(),
|
||
|
|
fill=1,
|
||
|
|
width=width)
|
||
|
|
# if we are not filling the polygon exit
|
||
|
|
if not fill:
|
||
|
|
del edraw
|
||
|
|
return exteriors
|
||
|
|
|
||
|
|
# draw the interiors
|
||
|
|
interiors = Image.new(mode='1', size=resolution)
|
||
|
|
idraw = ImageDraw.Draw(interiors)
|
||
|
|
for i, points in enumerate(discrete):
|
||
|
|
# draw the polygon on either the exterior or
|
||
|
|
# interior image buffer
|
||
|
|
if i in roots:
|
||
|
|
edraw.polygon(points.flatten().tolist(),
|
||
|
|
fill=1)
|
||
|
|
else:
|
||
|
|
idraw.polygon(points.flatten().tolist(),
|
||
|
|
fill=1)
|
||
|
|
# clean up the draw objects
|
||
|
|
# this is in the PIL examples and I have
|
||
|
|
# no idea if it this is actually necessary
|
||
|
|
del edraw
|
||
|
|
del idraw
|
||
|
|
# the final result is the exteriors minus the interiors
|
||
|
|
raster = ImageChops.subtract(exteriors, interiors)
|
||
|
|
|
||
|
|
return raster
|