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

174 lines
5.6 KiB
Python

#!/usr/bin/env python3
# Copyright (C) 2022 Samir OUCHENE, samirmath01@gmail.com
import os
import sys
import io
import inkex
from inkex import Image
from PIL import Image as PIL_Image
from PIL.Image import Transform, Resampling
import base64
import numpy
try:
from base64 import decodebytes
except ImportError:
from base64 import decodestring as decodebytes
class RasterPerspective(inkex.Effect):
def __init__(self):
inkex.Effect.__init__(self)
@staticmethod
def mime_to_ext(mime):
"""Return an extension based on the mime type"""
# Most extensions are automatic (i.e. extension is same as minor part of mime type)
part = mime.split("/", 1)[1].split("+")[0]
return (
"."
+ {
# These are the non-matching ones.
"svg+xml": ".svg",
"jpeg": ".jpg",
"icon": ".ico",
}.get(part, part)
)
def extract_image(self, node):
"""Extract the node as if it were an image."""
xlink = node.get("xlink:href")
if not xlink.startswith("data:"):
return # Not embedded image data
try:
data = xlink[5:]
(mimetype, data) = data.split(";", 1)
(base, data) = data.split(",", 1)
except ValueError:
inkex.errormsg("Invalid image format found")
return
if base != "base64":
inkex.errormsg("Can't decode encoding: {}".format(base))
return
file_ext = self.mime_to_ext(mimetype)
return decodebytes(data.encode("utf-8"))
def find_coeffs(self, source_coords, target_coords):
matrix = []
for s, t in zip(source_coords, target_coords):
matrix.append([t[0], t[1], 1, 0, 0, 0, -s[0] * t[0], -s[0] * t[1]])
matrix.append([0, 0, 0, t[0], t[1], 1, -s[1] * t[0], -s[1] * t[1]])
A = numpy.array(matrix, dtype=float)
B = numpy.array(source_coords).reshape(8)
res = numpy.linalg.inv(A.T @ A) @ A.T @ B
return numpy.array(res).reshape(8)
def effect(self):
WARN = "Your selection must contain an image and a path with at least 4 points."
if len(self.options.ids) < 2:
inkex.errormsg(WARN)
exit()
the_image_node, envelope_node = self.svg.selection
if str(envelope_node) == "image" and str(the_image_node) == "path":
envelope_node, the_image_node = self.svg.selection #switch
if str(the_image_node) != "image" or str(envelope_node) != "path":
inkex.errormsg(WARN)
exit()
img_width, img_height = the_image_node.width, the_image_node.height
try:
unit_to_vp = self.svg.unit_to_viewport
except AttributeError:
unit_to_vp = self.svg.uutounit
try:
vp_to_unit = self.svg.viewport_to_unit
except AttributeError:
vp_to_unit = self.svg.unittouu
img_width = unit_to_vp(img_width)
img_height = unit_to_vp(img_height)
nodes_pts = list(envelope_node.path.control_points)
node1 = (unit_to_vp(nodes_pts[0][0]), unit_to_vp(nodes_pts[0][1]))
node2 = (unit_to_vp(nodes_pts[1][0]), unit_to_vp(nodes_pts[1][1]))
node3 = (unit_to_vp(nodes_pts[2][0]), unit_to_vp(nodes_pts[2][1]))
node4 = (unit_to_vp(nodes_pts[3][0]), unit_to_vp(nodes_pts[3][1]))
nodes = [node1, node2, node3, node4]
xMax = max([node[0] for node in nodes])
xMin = min([node[0] for node in nodes])
yMax = max([node[1] for node in nodes])
yMin = min([node[1] for node in nodes])
# add some assertions (FIXME)
img_data = self.extract_image(the_image_node)
orig_image = PIL_Image.open(io.BytesIO(img_data))
pil_img_size = orig_image.size
scale = pil_img_size[0] / img_width
coeffs = self.find_coeffs(
[
(0, 0),
(img_width * scale, 0),
(img_width * scale, img_height * scale),
(0, img_height * scale),
],
[
(node1[0] - xMin, node1[1] - yMin),
(node2[0] - xMin, node2[1] - yMin),
(node3[0] - xMin, node3[1] - yMin),
(node4[0] - xMin, node4[1] - yMin),
],
)
W, H = xMax - xMin, yMax - yMin
final_w, final_h = int(W), int(H)
# Check if the image has transparency
hasTransparency = orig_image.mode in ("RGBA", "LA") or (
orig_image.mode == "P" and "transparency" in orig_image.info
)
transp_img = orig_image
# If the original image is not transparent, create a new image with alpha channel
if not hasTransparency:
transp_img = PIL_Image.new("RGBA", orig_image.size)
transp_img.format = "PNG"
transp_img.paste(orig_image)
image = transp_img.transform(
(final_w, final_h), Transform.PERSPECTIVE, coeffs, Resampling.BICUBIC
)
obj = inkex.Image()
obj.set("x", vp_to_unit(xMin))
obj.set("y", vp_to_unit(yMin))
obj.set("width", vp_to_unit(final_w))
obj.set("height", vp_to_unit(final_h))
# embed the transformed image
persp_img_data = io.BytesIO()
image.save(persp_img_data, transp_img.format)
mime = PIL_Image.MIME[transp_img.format]
b64 = base64.b64encode(persp_img_data.getvalue()).decode("utf-8")
uri = f"data:{mime};base64,{b64}"
obj.set("xlink:href", uri)
self.svg.add(obj)
RasterPerspective = RasterPerspective()
RasterPerspective.run()