# Copyright (c) 2017, System Engineering Software Society
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# * Neither the name of the System Engineering Software Society nor the
# names of its contributors may be used to endorse or promote products
# derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.
# IN NO EVENT SHALL SYSTEM ENGINEERING SOFTWARE SOCIETY BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
from __future__ import (print_function, division, unicode_literals,
absolute_import)
from sympathy.api import node
from sympathy.api.nodeconfig import Port, Ports, Tag, Tags
import numpy as np
from sylib.imageprocessing.image import Image
from sylib.imageprocessing.algorithm_selector import ImageFiltering_abstract
[docs]class OverlayImages(ImageFiltering_abstract, node.Node):
name = 'Overlay Images'
author = 'Mathias Broxvall'
copyright = '(C) 2017 System Engineering Software Society'
version = '0.1'
icon = 'image_overlay.svg'
description = (
'Combines two images by layering the first (top port) image on top of '
'the other (bottom port) image\n, with choice for combining operator. '
'Images must have the same number of channels')
nodeid = 'syip.overlay'
tags = Tags(Tag.ImageProcessing.Layers)
default_parameters = {
'use alpha channel': 'Use last channel of source images as alpha channel',
'alpha': 'Alpha value used when no alpha channel is given'
}
algorithms = {
'additive': dict({
'description': 'Adds the two images together where they overlap.',
'unity': 0.0,
'expr': lambda result, im: result + im,
'multichromatic': True
}, **default_parameters),
'multiplicative': dict({
'description': 'Multiplies images where they overlap.',
'unity': 1.0,
'expr': lambda result, im: result * im,
'multichromatic': True
}, **default_parameters),
'divide': dict({
'description': 'Divides bottom image by all other images.',
'unity': 1.0,
'expr': lambda result, im: result / im,
'multichromatic': True
}, **default_parameters),
'subtract': dict({
'description': 'Subtracts top image from bottom.',
'unity': 0.0,
'expr': lambda result, im: result - im,
'multichromatic': True
}, **default_parameters),
'max': dict({
'description': 'Takes the maximum value of the images.',
'unity': 0.0,
'expr': lambda result, im: np.maximum(result, im),
'multichromatic': True
}, **default_parameters),
'min': dict({
'description': 'Takes the minimum value of the images.',
'unity': 0.0,
'expr': lambda result, im: np.minimum(result, im),
'multichromatic': True
}, **default_parameters),
'layer': dict({
'description': (
'Layers on image on top of the other, alpha channel (if any) '
'determines transparency. Otherwise alpha value below'),
'unity': 0.0,
'expr': lambda result, im: im,
'multichromatic': True
}, **default_parameters),
}
options_list = [
'use alpha channel', 'alpha'
]
options_types = {
'use alpha channel': bool, 'alpha': float
}
options_default = {
'use alpha channel': False, 'alpha': 1.0
}
parameters = node.parameters()
parameters.set_string(
'algorithm', value=next(iter(algorithms)), description='',
label='Algorithm')
ImageFiltering_abstract.generate_parameters(
parameters, options_types, options_default)
inputs = Ports([
Port.Custom('image', 'Input images', name='images', n=(2,))
])
outputs = Ports([
Image('result after filtering', name='result'),
])
__doc__ = ImageFiltering_abstract.generate_docstring(
description, algorithms, options_list, inputs, outputs)
def execute(self, node_context):
images = [
obj.get_image() for obj in node_context.input.group('images')]
params = node_context.parameters
alg_name = params['algorithm'].value
use_alpha = params['use alpha channel'].value
# Reshape so all images guaranteed to have 3 dimensions
images = [
(im.reshape(im.shape + (1,)) if len(im.shape) < 3 else im)
for im in images]
# Compute max size
max_y = max([im.shape[0] for im in images])
max_x = max([im.shape[1] for im in images])
max_c = max([im.shape[2] for im in images])
if alg_name == 'multiplicative':
unity = 1.0
elif alg_name == 'divide':
unity = 1.0
else:
unity = 0.0
result = np.full((max_y, max_x, max_c), unity)
if any([im.dtype.kind == 'c' for im in images]):
result = result.astype(np.complex)
bot = images[-1]
result[:bot.shape[0], :bot.shape[1], :bot.shape[2]] = bot
rest = images[:-1]
alpha = params['alpha'].value
for im in rest[::-1]:
for c in range(im.shape[2]):
expr = OverlayImages.algorithms[alg_name]['expr']
y, x, _ = im.shape
if use_alpha:
result[:y, :x, c] = (
result[:y, :x, c] * (1-im[:, :, -1]) +
im[:, :, -1] * expr(result[:y, :x, c], im[:, :, c]))
else:
result[:y, :x, c] = (
result[:y, :x, c] * (1-alpha) +
alpha * expr(result[:y, :x, c], im[:, :, c]))
node_context.output['result'].set_image(result)
