R: Create Colour-Valued Pixel Image

rgbim {spatstat.geom} | R Documentation

## Create Colour-Valued Pixel Image

### Description

Creates an object of class `"im"` representing a two-dimensional pixel image whose pixel values are colours.

### Usage

      rgbim(R, G, B, A, maxColorValue=255, autoscale=FALSE)
      hsvim(H, S, V, A, autoscale=FALSE)

### Arguments

`R,G,B` | Pixel images (objects of class `"im"`) or constants giving the red, green, and blue components of a colour, respectively.
`A` | Optional. Pixel image or constant value giving the alpha (transparency) component of a colour.
`maxColorValue` | Maximum colour channel value for `R,G,B,A`.
`H,S,V` | Pixel images (objects of class `"im"`) or constants giving the hue, saturation, and value components of a colour, respectively.
`autoscale` | Logical. If `TRUE`, input values are automatically rescaled to fit the permitted range. RGB values are scaled to lie between 0 and `maxColorValue`. HSV values are scaled to lie between 0 and 1.

### Details

These functions take three pixel images, with real or integer pixel values, and create a single pixel image whose pixel values are colours recognisable to R.

Some of the arguments may be constant numeric values, but at least one of the arguments must be a pixel image. The image arguments should be compatible (in array dimension and in spatial position).

`rgbim` calls `rgb` to compute the colours, while `hsvim` calls `hsv`. See the help for the relevant function for more information about the meaning of the colour channels.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner r.turner@auckland.ac.nz and Ege Rubak rubak@math.aau.dk.

### See Also

`im.object`, `rgb`, `hsv`.

See `colourtools` for additional colour tools.

### Examples

      # create three images with values in [0,1]
      X <- setcov(owin())
      X <- eval.im(pmin(1,X))
      M <- Window(X)
      Y <- as.im(function(x,y){(x+1)/2}, W=M)
      Z <- as.im(function(x,y){(y+1)/2}, W=M)
      # convert
      RGB <- rgbim(X, Y, Z, maxColorValue=1)
      HSV <- hsvim(X, Y, Z)
      opa <- par(mfrow=c(1,2))
      plot(RGB, valuesAreColours=TRUE)
      plot(HSV, valuesAreColours=TRUE)
      par(opa)

[Package spatstat.geom version 2.2-0 Index]