Source code for node_transform

# This file is part of Sympathy for Data.
# Copyright (c) 2017, Combine Control Systems AB
#
# SYMPATHY FOR DATA COMMERCIAL LICENSE
# You should have received a link to the License with Sympathy for Data.
import numpy as np
import skimage

from sympathy.api import node
from sympathy.api.nodeconfig import Ports

from skimage import transform
from sylib.imageprocessing.image import ImagePort
from sylib.imageprocessing.algorithm_selector import ImageFiltering_abstract
from sylib.imageprocessing.generic_filtering import GenericImageFiltering

from packaging import version
skimage_version = version.Version(skimage.__version__)

# Test for deprecation of criterion arguments
check_19 = skimage_version >= version.Version('0.19.0')


def resize_args(im, params):
    if not check_19:
        return transform.rescale(
                im, (params['scale y'].value, params['scale x'].value),
                mode='constant',
                multichannel=True,
                anti_aliasing=True,
                order=params['interpolation degree'].value)
    else:
        return transform.rescale(
                im, (params['scale y'].value, params['scale x'].value),
                mode='constant',
                channel_axis=2,
                anti_aliasing=True,
                order=params['interpolation degree'].value)


def alg_resize(im, params):
    req_h = params['height'].value
    req_w = params['width'].value
    h, w = req_h, req_w
    if params['aspect'].value:
        aspect = im.shape[1] / float(im.shape[0])
        size = min(req_w / aspect, req_h)
        w = int(size * aspect)
        h = int(size)

    shape = (h, w) + im.shape[2:]
    result_im = transform.resize(
        im, shape, order=params['interpolation degree'].value,
        mode='constant', anti_aliasing=True)
    if params['padding'].value:
        pad_h = req_h - h
        pad_w = req_w - w
        padded_im = np.zeros((req_h, req_w) + im.shape[2:])
        x0 = int(pad_w/2)
        x1 = x0 + result_im.shape[1]
        y0 = int(pad_h/2)
        y1 = y0 + result_im.shape[0]
        padded_im[y0:y1, x0:x1] = result_im
        return padded_im
    return result_im


def alg_padding(im, params):
    if len(im.shape) < 3:
        im = im.reshape(im.shape+(1,))
    add_alpha = params['add alpha'].value
    px, py = params['x'].value, params['y'].value
    px, py = int(px), int(py)
    k = params['k'].value
    max_x = im.shape[1]+abs(px)
    max_y = im.shape[0]+abs(py)
    result = np.full((max_y, max_x, im.shape[2]+add_alpha), k)
    if add_alpha:
        result[max(0, py):max(0, py)+im.shape[0],
               max(0, px):max(0, px)+im.shape[1], :-1] = im
        result[max(0, py):max(0, py)+im.shape[0],
               max(0, px):max(0, px)+im.shape[1], -1] = np.ones(im.shape[:2])
    else:
        result[max(0, py):max(0, py)+im.shape[0],
               max(0, px):max(0, px)+im.shape[1]] = im
    return result


def alg_crop_image(im, params):
    x, y = params['x'].value, params['y'].value
    w, h = params['width'].value, params['height'].value
    shape = im.shape
    x, y = min(x, shape[1]), min(y, shape[0])
    w, h = min(w, shape[1]-x), min(h, shape[0]-y)
    return im[y:y+h, x:x+w]


API_URL = 'http://scikit-image.org/docs/0.13.x/api/'
INTERPOLATION_DEGREE_DESC = (
    'Degree of polynomial (0 - 5) used for interpolation.\n'
    '0 - no interpolation, 1 - bi-linear interpolation, '
    '3 - bi-cubic interpolation'
)

TRANSFORM_ALGS = {
    'resize': {
        'description': 'Resizes an image to match the given dimensions',
        'width': 'The new width of the image',
        'height': 'The new height of the image',
        'interpolation degree': INTERPOLATION_DEGREE_DESC,
        'multi_chromatic': True,
        'aspect': 'Preserve aspect ratio (gives smaller size on one axis)',
        'padding': (
            'Adds padding to fill out full width/height after '
            'aspect-correct scaling'),
        'url': API_URL+'skimage.transform.html#skimage.transform.resize',
        'algorithm': alg_resize
    },
    'rescale': {
        'description': 'Rescales an image by a given factor',
        'scale x': 'Scale factor along X direction (horizontal)',
        'scale y': 'Scale factor along Y direction (vertical)',
        'interpolation degree': INTERPOLATION_DEGREE_DESC,
        'multi_chromatic': True,
        'url': API_URL+'skimage.transform.html#skimage.transform.rescale',
        'algorithm': resize_args
    },
    'rotate': {
        'description': 'Rotates an image',
        'angle': 'Angular degrees to rotate counterclockwise',
        'resize': (
            'If true new image dimensions are calculated '
            'to exactly fit the image'),
        'multi_chromatic': True,
        'url': API_URL+'skimage.transform.html#skimage.transform.rotate',
        'algorithm': lambda im, par: transform.rotate(
            np.copy(im), par['angle'].value, resize=par['resize'].value)
    },
    'padding': {
        'description': 'Adds a padding to an image',
        'x': (
            'If positive, amount of padding added on the left side. '
            'If negative the amount of padding added on the right side.'),
        'y': ('If positive, amount of padding added on the top.'
              'If negative the amount of padding added on the bottom.'),
        'k': 'Constant value used in padded areas',
        'add alpha': (
            'Adds an alpha with value 1.0 inside image, 0.0 outside'),
        'multi_chromatic': True,
        'algorithm': alg_padding,
    },
    'crop': {
        'description': 'Crops the image to the given rectanglular area',
        'x': 'Left edge of image',
        'y': 'Top edge of image',
        'width': 'Width of image',
        'height': 'Height of image',
        'multi_chromatic': False,
        'algorithm': alg_crop_image,
    },
}

TRANSFORM_PARAMETERS = [
    'x', 'y', 'width', 'height', 'padding', 'aspect', 'interpolation degree',
    'scale x', 'scale y', 'angle', 'resize', 'k', 'add alpha'
]
TRANSFORM_TYPES = {
    'angle': float, 'scale y': float, 'scale x': float, 'k': float,
    'height': int, 'padding': bool, 'width': int, 'aspect': bool,
    'y': int, 'x': int, 'interpolation degree': int,
    'add alpha': bool, 'resize': bool
}
TRANSFORM_DEFAULTS = {
    'angle': 0.0, 'scale y': 1.0, 'scale x': 1.0, 'k': 0.05, 'height': 512,
    'padding': False, 'width': 512, 'aspect': False, 'y': 0, 'x': 0,
    'interpolation degree': 3, 'add alpha': False, 'resize': True
}


[docs] class TransformFilter(ImageFiltering_abstract, GenericImageFiltering, node.Node): name = 'Transform image' icon = 'image_transform.svg' description = ( 'Transforms and image into another shape') nodeid = 'syip.transform' algorithms = TRANSFORM_ALGS options_list = TRANSFORM_PARAMETERS options_types = TRANSFORM_TYPES options_default = TRANSFORM_DEFAULTS 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([ ImagePort('source image to filter', name='source'), ]) outputs = Ports([ ImagePort('result after filtering', name='result'), ]) __doc__ = ImageFiltering_abstract.generate_docstring( description, algorithms, options_list, inputs, outputs)