image2data {image2data} | R Documentation |
Turn an image into data
Description
Extract an image file ("png", "tiff", "jpeg", "bmp"
) and turn it into an enjoyable data set, pixels being rows (subjects) and columns (variables) being their coordinate positions (x and y axis) and their respective color (in hex codes).
Usage
image2data(
path,
type = "fill",
scaling = "standardized",
showplot = TRUE,
reduce = 1,
A = 1,
R = c(0, 0.05),
G = c(0, 0.05),
B = c(0, 0.05),
Grey = NULL,
precision = 1,
seed = NULL
)
Arguments
path |
Path to image file.
|
type |
Type of extraction of data. type = "fill" (default) returns the complete image as data whereas type = "line"
returns a specific range of color (default is black).
|
scaling |
Tranform the data to a specified scale. Three options are available : "standardized", "original", "normalized") . scaling = "standardized" converts data in a standardized form, \mu = 0, \sigma = 1 (default); scaling = "normalized" converts data in a normalized form (to unit vectors); and scaling = "original" keeps the data untransformed.
|
showplot |
Show a preliminary plot of the data (default is TRUE ).
|
reduce |
reduce can be a number reduce > 0 or reduce = "unique" . By default reduce = 1 , so all pixels are returned. Specified values between 0 to 1 will return the corrresponding proportion of the pixels. Values over 1 will return the number of pixels (e.g., reduce = 3 returns 3 data). If the chosen number is over the number of pixels, then random duplicates are added. If reduce = "unique" only unique elements (given a certain precision ) are returned.
|
A |
Transparency, otherwise known as \alpha . By default, only non transparent (A = 1 ) values are returned. Semi-transparent colors (0 < A < 1 ) are supported. Values between the A to 1 range will be return. If A = 0 , all pixels are returned regardless of transparency.
|
R , G , B |
Color to return with type = "line" (the default range is c(0, .05) for each, i.e., black). A single "range" of color can be used.
|
Grey |
Grey range to be returned with type = "line" . Grey overwrites R, G, B and behaves similarly. Default is NULL
|
precision |
Set precision of reduce = "unique" . Default is 1 . It can be any integer >0 . Values closer to zero are less precised (less data), higher values are more precise (more data).
|
seed |
Set seed value for random pixel returned with reduce .
|
Value
A data frame with pixels as rows and columns are x and y coordinates and g is their color in hex (factors).
Examples
path <- system.file(file.path("extdata", "success.png"), package = "image2data")
image2data(path = path, type = "line")
image2data(path = path, type = "line", Grey = c(0,.50))
## Not run:
image2data(path = file.choose())
## End(Not run)
[Package
image2data version 1.0.1
Index]