Color and image color mode conversions

Description

channel handles color space conversions between image modes. rgbImage combines Grayscale images into a Color one. toRGB is a wrapper function for convenient grayscale to RGB color space conversion; the call toRGB(x) returns the result of channel(x, 'rgb').

Usage

 
channel(x, mode)
rgbImage(red, green, blue)
toRGB(x)

Arguments

Details

Conversion modes:

rgb

Converts a Grayscale image or an array into a Color image, replicating RGB channels.

gray, grey

Converts a Color image into a Grayscale image, using uniform 1/3 RGB weights.

luminance

Luminance-preserving Color to Grayscale conversion using CIE 1931 luminance weights: 0.2126 * R + 0.7152 * G + 0.0722 * B.

red, green, blue

Extracts the red, green or blue channel from a Color image. Returns a Grayscale image.

asred, asgreen, asblue

Converts a Grayscale image or an array into a Color image of the specified hue.

NOTE: channel changes the pixel intensities, unlike colorMode which just changes the way that EBImage renders an image.

Value

An Image object or an array.

Author(s)

Oleg Sklyar, osklyar@ebi.ac.uk

See Also

colorMode

Examples

 x = readImage(system.file("images", "shapes.png", package="EBImage"))
 display(x)
 y = channel(x, 'asgreen')
 display(y)

 ## rgbImage
 x = readImage(system.file('images', 'nuclei.tif', package='EBImage'))
 y = readImage(system.file('images', 'cells.tif', package='EBImage'))
 display(x, title='Cell nuclei')
 display(y, title='Cell bodies')

 cells = rgbImage(green=1.5*y, blue=x)
 display(cells, title='Cells')

Results

R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

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Type 'demo()' for some demos, 'help()' for on-line help, or
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> library(EBImage)
> png(filename="/home/ddbj/snapshot/RGM3/R_BC/result/EBImage/channel.Rd_%03d_medium.png", width=480, height=480)
> ### Name: channel
> ### Title: Color and image color mode conversions
> ### Aliases: channel rgbImage toRGB
> 
> ### ** Examples
> 
>  x = readImage(system.file("images", "shapes.png", package="EBImage"))
>  display(x)
>  y = channel(x, 'asgreen')
>  display(y)
> 
>  ## rgbImage
>  x = readImage(system.file('images', 'nuclei.tif', package='EBImage'))
>  y = readImage(system.file('images', 'cells.tif', package='EBImage'))
>  display(x, title='Cell nuclei')
Only the first frame of the image stack is displayed.
To display all frames use 'all = TRUE'.
>  display(y, title='Cell bodies')
Only the first frame of the image stack is displayed.
To display all frames use 'all = TRUE'.
> 
>  cells = rgbImage(green=1.5*y, blue=x)
>  display(cells, title='Cells')
Only the first frame of the image stack is displayed.
To display all frames use 'all = TRUE'.
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>