OpenImageR (version 1.0)

Augmentation: image augmentations of a matrix, data frame, array or a list of 3-dimensional arrays

Description

image augmentations of a matrix, data frame, array or a list of 3-dimensional arrays

Usage

Augmentation(image, flip_mode = NULL, crop_width = NULL, crop_height = NULL, resiz_width = 0, resiz_height = 0, resiz_method = "nearest", shift_rows = 0, shift_cols = 0, rotate_angle = 0, rotate_method = "nearest", zca_comps = 0, zca_epsilon = 0, image_thresh = 0, threads = 1, verbose = FALSE)

Arguments

image

a matrix, data frame, array or list of 3-dimensional arrays

flip_mode

a character string ('horizontal', 'vertical')

crop_width

an integer specifying the new width of the image, after the image is cropped. Corresponds to the image-rows.

crop_height

an integer specifying the new height of the image, after the image is cropped. Corresponds to the image-columns.

resiz_width

an integer specifying the new width of the image, after the image is resized. Corresponds to the image-rows.

resiz_height

an integer specifying the new height of the image, after the image is resized. Corresponds to the image-columns.

resiz_method

a string specifying the interpolation method when resizing an image ('nearest', 'bilinear')

shift_rows

a positive or negative integer specifying the direction that the rows should be shifted

shift_cols

a positive or negative integer specifying the direction that the columns should be shifted

rotate_angle

an integer specifying the rotation angle of the image

rotate_method

a string specifying the interpolation method when rotating an image ('nearest', 'bilinear')

zca_comps

an integer specifying the number of components to keep by zca whitening, when svd is performed

zca_epsilon

a float specifying the regularization parameter by zca whitening

image_thresh

the threshold parameter, by image thresholding, should be between 0 and 1 if the data is normalized or between 0-255 otherwise

threads

an integer specifying the number of cores to run in parallel ( applies only in case that the image parameter is an array )

verbose

a boolean (TRUE, FALSE). If TRUE, then the total time of the preprocessing task will be printed.

Value

the output is of the same type with the input (in case of a data frame it returns a matrix)

Details

This function takes advantage of various methods to accomplish image augmentations. The order of the preprocessing steps, in case that all transformations are applied to an image, is : 1st flip image, 2nd crop image, 3rd resize image, 4th shift rows or columns, 5th rotate image, 6th zca-whitening and 7th image-thresholding.

Examples

# a matrix
object = matrix(1, 10, 10)

res = Augmentation(object, resiz_width = 8, resiz_height = 8, rotate_angle = 40)


# an array
object = array(0, dim = c(10, 10, 3))

res = Augmentation(object, resiz_width = 8, resiz_height = 8, rotate_angle = 30)


# an array (multiple matrices)
object = array(0, dim = c(10, 10, 10))

res = Augmentation(object, resiz_width = 8, resiz_height = 8, rotate_angle = 20)


# a list of 3-dimensional arrays
object = list(array(0, dim = c(10, 10, 3)), array(0, dim = c(10, 10, 3)))                

res = Augmentation(object, resiz_width = 8, resiz_height = 8, rotate_angle = 40)