darsia.CurvatureCorrection#

class CurvatureCorrection(config=None, **kwargs)[source]#

Bases: BaseCorrection

Polynomial curvature correction.

Contains routines for setting up the curvature correction, as well as applying it to images.

Attributes:

configdict

Config dictionary for curvture correction.

Circumstantial attributes: reference_image (np.ndarray): image matrix of the reference image. current_image (np.ndarray): image matrix of the updated reference image. width (float): physical width of reference image. height (float): physical height of reference image. in_meters (bool): True if width/height is in meters. Ny (int): number of pixels in vertical direction in reference image. Nx (int): number of pixels in horizontal direction in reference image.

Set up the curvature correction.

Normally initialised from a config file that controls the correction routine. Initialising from an image path (not a darsia.Image) is only meant for building the config file interactively.

Parameters:

**kwargs

Either config or image must be given:

config (dict | str | Path)   config dictionary (default None)
image (Path | np.ndarray)    image source, as a path or an array
width (float)                physical image width (image mode)
height (float)               physical image height (image mode)
in_meters (bool)             whether width/height are in metres
                             (image mode)

Methods

`bulge_correction`([left, right, top, bottom])	Bulge correction
`compute_bulge`([img])	Compute the bulge parameters depending on the maximum number of pixels that the image has been displaced on each side.
`compute_stretch`([img])	Compute the stretch parameters depending on the stretch center, and a known translation.
`correct_array`(img)	Call method of the curvature correction.
`correct_metadata`([metadata])	Extract metadata from the config file.
`load`(path)	Load the curvature correction from a file.
`pre_bulge_correction`(**kwargs)	Force all straight lines to curve inwards rather than outwards.
`read_config_from_file`(path)	Reads a json-file to the config disctionary.
`return_image`()	Returns the current image as a darsia image width provided width and height.
`save`(path)	Save the curvature correction to a file.
`setup_config`([config])
`show_image`()	Shows the current image using matplotlib.pyplot
`simple_curvature_correction`(img, **kwargs)	General routine for applying stretch and bulge transforms.
`stretch_correction`(point_source, ...)	Stretch the image from the displacement of a single point.
`write_config_to_file`(path)	Writes the config dictionary to a json-file.

Attributes

temporary_image

bulge_correction(left=0, right=0, top=0, bottom=0)[source]#

Bulge correction

Corrects bulging of image, depending on the amount of pixels that the image is bulged inwards on each side.

Parameters:

leftint: Amount of bulged pixels on the left side of the image.
rightint: Amount of bulged pixels on the right side of the image.
topint: Amount of bulged pixels on the top of the image.
bottomint: Amount of bulged pixels on the bottom of the image.

compute_bulge(img=None, **kwargs)[source]#

Compute the bulge parameters depending on the maximum number of pixels that the image has been displaced on each side.

Parameters:

imgnp.ndarray, optional: Image array, basis for the computation.
**kwargsoptional keyword arguments: “left” (int): the maximum number of pixels that the image has been displaced on the left side “right” (int): the maximum number of pixels that the image has been displaced on the right side “top” (int): the maximum number of pixels that the image has been displaced on the top “bottom” (int): the maximum number of pixels that the image has been displaced on the bottom.

compute_stretch(img=None, **kwargs)[source]#

Compute the stretch parameters depending on the stretch center, and a known translation.

Parameters:

imgnp.ndarray, optional: Image array, basis for the computation.
**kwargsoptional keyword arguments: “point_source” (list): point that has been translated. “point_destination” (list): the ought to be position. “stretch_center” (list): the stretch center.

correct_array(img)[source]#

Call method of the curvature correction.

Applies the curvature correction to a provided image, and returns the corrected image as an array. If set in the constructor, the image will be resized in the first step.

Parameters:

imgnp.ndarray: Image array.

Returns:

np.ndarray: Curvature corrected image.

correct_metadata(metadata={})[source]#

Extract metadata from the config file.

Parameters:

metadatadict, optional: Metadata dictionary to be updated. Defaults to {}.

Returns:

dict: Metadata.

load(path)[source]#

Load the curvature correction from a file.

Parameters:

pathPath: Path to the file.

pre_bulge_correction(**kwargs)[source]#

Force all straight lines to curve inwards rather than outwards.

Parameters:

**kwargs

Curvature parameters:

horizontal_bulge (float)          horizontal bulge
horizontal_center_offset (int)    x offset of the image centre
                                  from the numerical centre, px
vertical_bulge (float)            vertical bulge
vertical_center_offset (int)      y offset of the image centre
                                  from the numerical centre, px

read_config_from_file(path)[source]#

Reads a json-file to the config disctionary.

Parameters:

pathPath: Path to the json-file.

return_image()[source]#: Returns the current image as a darsia image width provided width and height.

save(path)[source]#

Save the curvature correction to a file.

Parameters:

pathPath: Path to the file.

show_image()[source]#: Shows the current image using matplotlib.pyplot

simple_curvature_correction(img, **kwargs)[source]#

General routine for applying stretch and bulge transforms. This routine in contrast to __call__ does always use the keyword arguments and constructs the transformation instead of using cached values.

Parameters:

imgnp.ndarray: Image array.
**kwargsoptional keyword arguments: See _transform_coordinates for more details.

Returns:

np.ndarray: Corrected image.

stretch_correction(point_source, point_destination, stretch_center)[source]#

Stretch the image from the displacement of a single point.

The image is stretched given a point’s displacement (point_source -> point_destination) and one undisplaced point (stretch_center).

Parameters:

point_sourcelist: Point that has been translated.
point_destinationlist: Its intended position.
stretch_centerlist: The undisplaced (stretch centre) point.

write_config_to_file(path)[source]#

Writes the config dictionary to a json-file.

Parameters:

pathPath: Path to the json file.