mightyscape-1.2/extensions/fablabchemnitz/pixels2objects/pixels2objects.py

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2022-10-03 03:07:44 +02:00
#! /usr/bin/python3
'''
Copyright (C) 2021 Scott Pakin, scott-ink@pakin.org
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA.
'''
import base64
import inkex
import io
import PIL.Image
import random
import sys
class PixelsToObjects(inkex.EffectExtension):
"Copy an object to the coordinates of each pixel in an image."
def add_arguments(self, pars):
'Process program parameters passed in from the UI.'
pars.add_argument('--tab', help='The selected UI tab when OK was pressed')
pars.add_argument('--scale', type=float, help='Factor by which to scale image coordinates')
pars.add_argument('--color-stroke', type=inkex.Boolean, help="Color the object's stroke to match the pixel color")
pars.add_argument('--color-fill', type=inkex.Boolean, help='Fill the object with the pixel color')
pars.add_argument('--ignore-bg', type=inkex.Boolean, help='Ignore background-colored pixels')
pars.add_argument('--obj-select', choices=['coords', 'rr', 'random'], help='Specify how to iterate among multiple selected objects')
def _get_selection(self):
'Return an image and an object.'
# Bin the objects in the current selection.
img = None
objs = []
for s in self.svg.selection.values():
if isinstance(s, inkex.Image):
if img == None:
img = s # First image encountered
else:
objs.append(s) # All remaining images are consider "other" objects
else:
objs.append(s) # All non-images are "other" objects
# Ensure the selection is valid.
if img == None or objs == []:
inkex.utils.errormsg(_('Pixels to Objects requires that one image and at least one additional object be selected.'))
sys.exit(1)
return img, objs
def _generate_coords2obj(self, objs):
'''Return a function that maps pixel coordinates to an object in a
given list of SVG objects.'''
n_objs = len(objs)
obj_select = self.options.obj_select
if obj_select == 'coords':
return lambda x, y: objs[(x + y)%n_objs]
if obj_select == 'rr':
idx = 0
def coords2obj_rr(x, y):
nonlocal idx
obj = objs[idx]
idx = (idx + 1)%len(objs)
return obj
return coords2obj_rr
if obj_select == 'random':
return lambda x, y: objs[random.randint(0, n_objs - 1)]
inkex.errormessage(_('internal error: unhandled object-selection type "%s"' % obj_select))
sys.exit(1)
def _copy_object_to(self, obj, xy):
'''Copy an object and center the copy on the given coordinates,
optionally recoloring its stroke and/or fill'''
# Create a transform that moves the object to the origin.
xform = inkex.Transform(obj.get('transform'))
pos = obj.bounding_box(obj.composed_transform()).center
xform.add_translate(-pos)
# Modify the transform to move the object to the target coordinates.
xform.add_translate(xy)
# Duplicate the object and apply the transform.
new_obj = obj.duplicate()
new_obj.update(transform=xform)
return new_obj
def _read_image(self, img_elt):
'Read an image from either the SVG file itself or an external file.'
# Read the image from an external file.
fname = img_elt.get('sodipodi:absref')
if fname != None:
# Fully qualified filename. Read it directly.
return PIL.Image.open(fname)
xlink = img_elt.get('xlink:href')
if not xlink.startswith('data:'):
# Unqualified filename. Try reading it directly although there's a
# good chance this will fail.
return PIL.Image.open(fname)
# Read an image embedded in the SVG file itself.
try:
mime, dtype_data = xlink[5:].split(';', 1)
dtype, data64 = dtype_data.split(',', 1)
except ValueError:
inkex.errormsg('failed to parse embedded image data')
sys.exit(1)
if dtype != 'base64':
inkex.errormsg('embedded image is encoded as %s, but this plugin supports only base64' % dtype)
sys.exit(1)
raw_data = base64.decodebytes(data64.encode('utf-8'))
return PIL.Image.open(io.BytesIO(raw_data))
def _guess_background_color(self, img):
'Return the most commonly occurring color, assuming it represents the background.'
wd, ht = img.size
tally, bg_color = max(img.getcolors(wd*ht))
return bg_color
def _pixels_to_objects(self, img, coords2obj, bg_color, scale, change_stroke, change_fill):
'''Perform the core functionality of this extension, using pixel
coordinates to place object replicas.'''
# Create a new group for all the objects we'll create.
group = inkex.Group()
parent = self.svg.selection.first().getparent()
parent.add(group)
# Convert each pixel to a replica of the object, optionally
# recoloring it.
wd, ht = img.size
for y in range(ht):
for x in range(wd):
xy = (x, y)
pix = img.getpixel(xy)
if pix == bg_color:
continue
obj = coords2obj(x, y)
new_obj = self._copy_object_to(obj, inkex.Vector2d(xy)*scale)
if change_stroke:
new_obj.style['stroke'] = '#%02x%02x%02x' % (pix[0], pix[1], pix[2])
new_obj.style['stroke-opacity'] = '%.10g' % (pix[3]/255.0)
if change_fill:
new_obj.style['fill'] = '#%02x%02x%02x' % (pix[0], pix[1], pix[2])
new_obj.style['fill-opacity'] = '%.10g' % (pix[3]/255.0)
group.add(new_obj)
def effect(self):
'''Given a bitmap image and an object, copy the object to each
coordinate of the image that contains a colored pixel.'''
img_elt, objs = self._get_selection()
img = self._read_image(img_elt).convert('RGBA')
if self.options.ignore_bg:
bg_color = self._guess_background_color(img)
else:
bg_color = None
scale = self.options.scale
change_stroke = self.options.color_stroke
change_fill = self.options.color_fill
coords2obj = self._generate_coords2obj(objs)
self._pixels_to_objects(img, coords2obj, bg_color, scale, change_stroke, change_fill)
img.close()
if __name__ == '__main__':
PixelsToObjects().run()