ImageAccess - Documentation

new ImageAccess(height, widthopt, init_dictopt) → {ImageAccess}

Creates a new image of the specified height and width.

Properties:

Name	Type	Description
`image`	`Array`	The image stored as a 2D Array

Source:

ImageAccess.js, line 4

Parameters:

Name Type Attributes Description

height Integer | Array The height of the image, or an array of [height, width], or an existing 2D array

width Integer <optional> The width of the image

init_dict

Object

Object specifying the initial values for the image

Name	Type	Attributes	Default	Description
`init_value`	`Number`	<optional>	0	The initial value to set to all pixels
`rgb`	`Boolean`	<optional>	false	Boolean indicating if the image is rgb or not

Returns:

Type:: ImageAccess

Examples

Create a new image of dimensions width x height

new ImageAccess(height, width);

Provide height and width as an array

new ImageAccess([height, width]);

Create a new image with the same dimensions as an existing image img

new ImageAccess(img.shape());

Set the initial value to 255

new Image(height, width, {init_value:255});

Creating an image from an existing 2D Array arr

new Image(arr);

Methods

(static) applyBoundaryCondition(x, y, shap, paddingopt) → {Array}

Adjusts index values based on the shape and specified boudary conditions

Source:

ImageAccess.js, line 926

Parameters:

Name	Type	Attributes	Default	Description
`x`	`Integer`			The x index
`y`	`Integer`			The y index
`shap`	`Array`			The shape (size) of the image (`[ny, nx]`)
`padding`	`String`	<optional>	'mirror'	The boundary condition to apply ('mirror', 'repeat' or 'zero')

Returns:

Type:: Array

The modified indices as an array ([x, y])

(static) arrayCompare(a1, a2, erropt, tolopt, utilObjopt) → {Boolean}

Checks if two array are equal within a certain tolerance

Source:

ImageAccess.js, line 738

Parameters:

Name Type Attributes Default Description

a1 Array The first array

a2 Array The second array

err

Object

Object containing the error message

Name	Type	Attributes	Default	Description
`msg`	`Boolean`	<optional>	null	The error message, specifying the type of error and more info

tol Number <optional> 1e-5 The tolerance used for the comparison

utilObj

Object

Object containing internally used variables

Name	Type	Attributes	Description
`mismatch`	`Number`	<optional>	The mismatch ratio
`maxErr`	`Number`	<optional>	The maximum error between the two Arrays
`count`	`Number`	<optional>	The number of mismatched elements

Returns:

Type:: Boolean

true if the two Arrays are equal within the tolerance, false if not

(static) fromHTMLImageElement(htmlImageElement) → {ImageAccess}

Creates an ImageAccess object from an HTMLImageElement object

Source:

ImageAccess.js, line 1094

Parameters:

Name	Type	Description
`htmlImageElement`	`HTMLImageElement`	The HTMLImageElement where the image is stored

Returns:

Type:: ImageAccess

(static) getMax(arr) → {Number}

Calculates the maximum value of an array with arbitrary dimensions

Source:

ImageAccess.js, line 325

Parameters:

Name	Type	Description
`arr`	`Array`	The input Array

Returns:

Type:: Number

The maximum

(static) getMin(arr) → {Number}

Calculates the minimum value of an array with arbitrary dimensions

Source:

ImageAccess.js, line 339

Parameters:

Name	Type	Description
`arr`	`Array`	The input Array

Returns:

Type:: Number

The minimum

(static) getNbh(img, x_pos, y_pos, nx, ny, paddingopt) → {Array}

Returns a neighbourhood of an Array

Source:

ImageAccess.js, line 232

Parameters:

Name	Type	Attributes	Default	Description
`img`	`Array`			The 2D input Array
`x_pos`	`Integer`			The x position of the center of the neighbourhood
`y_pos`	`Integer`			The y position of the center of the neighbourhood
`nx`	`Integer`			The width of the neighbourhood
`ny`	`Integer`			The height of the neighbourhood
`padding`	`String`	<optional>	'mirror'	The boundary condition to apply ('mirror', 'repeat' or 'zero')

Returns:

Type:: Array

- The neighbourhood as a 2D Array

(static) isNormalizationError(img1, img2, copt, tolopt) → {Boolean}

Checks if there is a normalization error between two Arrays. A normalization error means that one array is a scalar multiple of the other.

Source:

ImageAccess.js, line 684

Parameters:

Name Type Attributes Default Description

img1 Array The first array

img2 Array The second array

c

Object

Name	Type	Attributes	Default	Description
`c`	`Number`	<optional>	null	The proportionality constant to check for. If not given it is calculated from the first pixel

tol Number <optional> 1e-3 The tolerance used for the comparison

Returns:

Type:: Boolean

true if it is a normalization error, false if not

(static) min(a, b) → {Number|Array}

Calculates the minimum per color channel of two color- or graylevel pixels

Source:

ImageAccess.js, line 294

Parameters:

Name	Type	Description
`a`	`Number` \| `Array`	The first pixel
`b`	`Number` \| `Array`	The second pixel

Returns:

Type:: Number | Array

- The minimum per color channel of the two pixels

(static) MultidimArray(init_value, height, widthopt, depthopt) → {Array}

Creates a 1D/2D/3D Array

Source:

ImageAccess.js, line 180

Parameters:

Name	Type	Attributes	Description
`init_value`	`Number`		The initial value to set to all elements of the array
`height`	`Integer`		The height of the array
`width`	`Integer`	<optional>	The width of the array
`depth`	`Integer`	<optional>	The depth of the array

Returns:

Type:: Array

An array of size height x width x depth initialized to init_value

(static) ndims(arr) → {Number}

Source:

ImageAccess.js, line 115

Parameters:

Name	Type	Description
`arr`	`Array`

Returns:

Type:: Number

The number of dimensions of an array

(static) shape(arr)

Source:

ImageAccess.js, line 146

Parameters:

Name	Type	Description
`arr`	`Array`

Returns:

The shape / size of an array

(static) transpose(array) → {Array}

Returns the transpose of an array

Source:

ImageAccess.js, line 658

Parameters:

Name	Type	Description
`array`	`Array`	The 2D input Array

Returns:

Type:: Array

The transposed Array

copy() → {ImageAccess}

Creates a copy of the image

Source:

ImageAccess.js, line 859

Returns:

Type:: ImageAccess

A copy of the image

displayImage(scaleopt, showPixelsopt, idopt) → {HTMLCanvasElement}

Returns an html canvas to display the image

Source:

ImageAccess.js, line 1031

Parameters:

Name	Type	Attributes	Default	Description
`scale`	`Number`	<optional>	1	The size scale of the image
`showPixels`	`Boolean`	<optional>	false	Indicates whether a pixel grid is drawn or not (only use for small images)
`id`	`String`	<optional>	''	The html canvas id to use

Returns:

Type:: HTMLCanvasElement

- The html canvas containing the image

fromArray(arr)

Updates the image from a provided array.

Source:

ImageAccess.js, line 79

Parameters:

Name	Type	Description
`arr`	`Array`	A 2D Array containing the image

getColumn(x, paddingopt) → {ImageAccess}

Returns the column at location x

Source:

ImageAccess.js, line 511

Parameters:

Name	Type	Attributes	Default	Description
`x`	`Integer`			The horizontal (x) location of the column
`padding`	`String`	<optional>	'mirror'	The boundary condition to apply ('mirror', 'repeat' or 'zero')

Returns:

Type:: ImageAccess

The column of pixels at location x

getMax(recalcopt) → {Number}

Returns the maximum value of the image

Source:

ImageAccess.js, line 354

Parameters:

Name	Type	Attributes	Default	Description
`recalc`	`Boolean`	<optional>	false	A boolean indicating if the maximum needs to be recalculated

Returns:

Type:: Number

- The maximum value of the image

getMin(recalcopt) → {Number}

Returns the minimum value of the image

Source:

ImageAccess.js, line 374

Parameters:

Name	Type	Attributes	Default	Description
`recalc`	`Boolean`	<optional>	false	A boolean indicating if the minimum needs to be recalculated

Returns:

Type:: Number

- The minimum value of the image

getNbh(x_pos, y_pos, nx, ny, paddingopt) → {Nbh_Access}

Returns a neighbourhood of the image

Source:

ImageAccess.js, line 278

Parameters:

Name	Type	Attributes	Default	Description
`x_pos`	`Integer`			The x position of the center of the neighbourhood
`y_pos`	`Integer`			The y position of the center of the neighbourhood
`nx`	`Integer`			The width of the neighbourhood
`ny`	`Integer`			The height of the neighbourhood
`padding`	`String`	<optional>	'mirror'	The boundary condition to apply ('mirror', 'repeat' or 'zero').

Returns:

Type:: Nbh_Access

- The neighbourhood

getPixel(x, y, paddingopt) → {Number}

Returns the pixel value at position (x,y)

Source:

ImageAccess.js, line 419

Parameters:

Name	Type	Attributes	Default	Description
`x`	`Integer`			The horizontal (x) position of the pixel
`y`	`Integer`			The vertical (y) position of the pixel
`padding`	`String`	<optional>	'mirror'	The boundary condition to apply ('mirror', 'repeat' or 'zero')

Returns:

Type:: Number

The pixel value

getRow(y, paddingopt) → {ImageAccess}

Returns the row of pixels at location y

Source:

ImageAccess.js, line 484

Parameters:

Name	Type	Attributes	Default	Description
`y`	`Integer`			The vertical (y) location of the row
`padding`	`String`	<optional>	'mirror'	The boundary condition to apply ('mirror', 'repeat' or 'zero')

Returns:

Type:: ImageAccess

The row of pixels at location y

getSubImage(x, y, nx, ny) → {ImageAccess}

Returns a sub-image from the image

Source:

ImageAccess.js, line 897

Parameters:

Name	Type	Description
`x`	`Integer`	The horizontal (x) location of the top-left corner of the sub-image
`y`	`Integer`	The vertical (y) location of the top-left corner of the sub-image
`nx`	`Integer`	The width of the sub-image
`ny`	`Integer`	The height of the sub-image

Returns:

Type:: ImageAccess

- The extracted sub-image

imageCompare(newImage, erropt, tolopt) → {Boolean}

Checks if this image is equal to another within a certain tolerance

Source:

ImageAccess.js, line 798

Parameters:

Name Type Attributes Default Description

newImage ImageAccess The second image to compare

err

Object

Object containing the error message

Name	Type	Attributes	Default	Description
`msg`	`Boolean`	<optional>	null	The error message, specifying the type of error and more info

tol Number <optional> 1e-5 The tolerance used for the comparison

Returns:

Type:: Boolean

true if the two images are equal within the tolerance, false if not

isNormalizationError(img) → {Boolean}

Checks if there is a normalization error between this image and another image. A normalization error means that one array is a scalar multiple of the other.

Source:

ImageAccess.js, line 721

Parameters:

Name	Type	Description
`img`	`ImageAccess`	The other image to compare

Returns:

Type:: Boolean

true if it is a normalization error, false if not

ndims() → {Number}

Source:

ImageAccess.js, line 136

Returns:

Type:: Number

The number of dimensions of the image

normalize() → {ImageAccess}

Maps the image to the range [0,1]

Source:

ImageAccess.js, line 394

Returns:

Type:: ImageAccess

The remapped image

putColumn(x, new_column, paddingopt)

Inserts a new column at location x

Source:

ImageAccess.js, line 599

Parameters:

Name	Type	Attributes	Default	Description
`x`	`Integer`			The horizontal (x) location of the column
`new_column`	`ImageAccess`			The new column to insert
`padding`	`String`	<optional>	'mirror'	The boundary condition to apply ('mirror', 'repeat' or 'zero')

putRow(y, new_row, paddingopt)

Inserts a row at location y

Source:

ImageAccess.js, line 538

Parameters:

Name	Type	Attributes	Default	Description
`y`	`Integer`			The vertical (y) position of the row
`new_row`	`ImageAccess`			The new row to insert
`padding`	`String`	<optional>	'mirror'	The boundary condition to apply ('mirror', 'repeat' or 'zero')

putSubImage(x, y, img)

Inserts another image into the image

Source:

ImageAccess.js, line 869

Parameters:

Name	Type	Description
`x`	`Integer`	The horizontal (x) location of the top-left corner of the sub-image
`y`	`Integer`	The vertical (y) location of the top-left corner of the sub-image
`img`	`ImageAccess`	The image to insert

setPixel(x, y, value, paddingopt)

Sets the pixel value at location (x,y)

Source:

ImageAccess.js, line 441

Parameters:

Name	Type	Attributes	Default	Description
`x`	`Integer`			The horizontal (x) position of the pixel
`y`	`Integer`			The vertical (y) position of the pixel
`value`	`Number`			The new value to which this pixel will be set
`padding`	`String`	<optional>	'mirror'	The boundary condition to apply ('mirror', 'repeat' or 'zero')

shape()

Source:

ImageAccess.js, line 167

Returns:

The shape / size of the image

sort(bopt) → {ImageAccess}

Returns the pixel values in ascending order

Source:

ImageAccess.js, line 808

Parameters:

Name	Type	Attributes	Description
`b`	`ImageAccess`	<optional>	The kernel. It should be the same size as the image and contain 0s and 1s (or any other number), specifying which pixels are used during the sorting. By default, all pixels are used