DipCoatImage-FiniteDepth-IFD documentation#

API reference#

Finite depth dip coating uniformity measurement using integral Fréchet distance.

To reproduce the examples, run the following code first:

import cv2
from finitedepth import *
from finitedepth_ifd import *

class finitedepth_ifd.IfdRoughnessBase(image, substrate, roughness_type, delta, *, tempmatch=None)[source]#

Base class to measure layer surface roughness with integral Fréchet distance.

The following types of roughness are supported:

Arithmetic roughness \(R_a\)
Quadratic mean roughness \(R_q\)

Parameters:

image, substrate: See CoatingLayerBase.
roughness_type{‘arithmetic’, ‘quadratic’}
deltadouble: The maximum distance between the Steiner points to compute the roughness. Refer to roughness() for more explanation.

Other Parameters:

tempmatchtuple, optional: See CoatingLayerBase.

abstract surface()[source]#

Coating layer surface points.

Returns:

ndarray: An \(N\) by \(2\) array containing the \(xy\)-coordinates of \(N\) points which constitute the coating layer surface profile.

abstract uniform_layer()[source]#

Imaginary uniform layer points.

Returns:

thicknessdouble: Thickness of the uniform layer.
ndarray: An \(M\) by \(2\) array containing the \(xy\)-coordinates of \(M\) points which constitute the uniform layer profile.

roughness()[source]#

Surface roughness of the coating layer.

Returns:

roughnessdouble: Roughness value.
pathndarray: An \(P\) by \(2\) array representing the optimal warping path in the parameter space.

See also

curvesimilarities.averagefrechet.afd: Average Fréchet distance.
curvesimilarities.averagefrechet.qafd: Quadratic average Fréchet distance.

Notes

The roughness is acquired by computing the similarity between surface() and uniform_layer().

class finitedepth_ifd.RectIfdRoughness(image, substrate, roughness_type, delta, opening_ksize, reconstruct_radius, *, tempmatch=None)[source]#

Measure layer surface roughness over rectangular substrate.

Parameters:

image: See CoatingLayerBase.
substrateRectSubstrate.: Substrate instance.
roughness_type, delta: See IfdRoughnessBase.
opening_ksizetuple of int: Kernel size for morphological opening operation. Must be zero or odd.
reconstruct_radiusint: Radius of the safe zone for noise removal. Two imaginary circles with this radius are drawn on bottom corners of the substrate. When extracting the coating layer, connected components not spanning over any of these circles are regarded as noise.

Other Parameters:

tempmatchtuple, optional: See CoatingLayerBase.

Examples

Construct the substrate instance first.

>>> ref_img = cv2.imread(get_sample_path("ref.png"), cv2.IMREAD_GRAYSCALE)
>>> ref = Reference(
...     cv2.threshold(ref_img, 0, 255, cv2.THRESH_BINARY | cv2.THRESH_OTSU)[1],
...     (10, 10, 1250, 200),
...     (100, 100, 1200, 500),
... )
>>> subst = RectSubstrate(ref, 3.0, 1.0, 0.01)

Construct the coating layer instance.

>>> target_img = cv2.imread(get_sample_path("coat.png"), cv2.IMREAD_GRAYSCALE)
>>> coat = RectIfdRoughness(
...     cv2.threshold(target_img, 0, 255, cv2.THRESH_BINARY | cv2.THRESH_OTSU)[1],
...     subst,
...     "arithmetic",
...     5.0,
...     (1, 1),
...     50,
... )

Visualize the coating layer.

>>> import matplotlib.pyplot as plt 
>>> plt.imshow(coat.draw()) 

(Source code, png, hires.png, pdf)

DataType#: alias of RectIfdRoughnessData

valid()[source]#

Check if the coating layer is valid.

The coating layer is invalid if the capillary bridge is not ruptured.

Returns:

bool

extract_layer()[source]#

Extract the coating layer region from the target image.

Returns:

ndarray of bool: An array where the coating layer region is True. Has the same shape as image.

Notes

The following operations are performed to remove the error pixels:

Image opening with opening_ksize attribute.
Reconstruct connected components using reconstruct_radius and and substrate vertices.

substrate_contour()[source]#: Return substrate’s contour in image.

interface_indices()[source]#

Return indices of the substrate contour for the solid-liquid interface.

The interface points can be retrieved by slicing the substrate contour with there indices.

Returns:

ndarray: Starting and ending indices for the solid-liquid interface, empty if the interface does not exist.

DipCoatImage-FiniteDepth-IFD documentation#

API reference#

Indices and tables#