display {EBImage} | R Documentation

## Image Display

### Description

Display images in an interactive JavaScript viewer or using R's built-in graphics capabilities.

### Usage

    display(x, method, ...)

    ## S3 method for class 'Image'
    plot(x, ...)

### Arguments

`x` | an `Image` object or an array.
`method` | the way of displaying images. Defaults to `"browser"` when R is used interactively, and to `"raster"` otherwise. The default behavior can be overridden by setting `options("EBImage.display")`. See Details.
`...` | arguments to be passed to the specialized display functions; for details see the sections on individual display methods.

### Details

The default `method` used for displaying images depends on whether called from and interactive R session. If `interactive()` is `TRUE` images are displayed with the `"browser"` method, otherwise the `"raster"` method is used. This dynamic behavior can be overridden by setting `options("EBImage.display")` to either `"browser"` or `"raster"`.

`plot.Image` S3 method is a wrapper for `display(..., method="raster")`

### "browser" method

The `"browser"` method runs an interactive JavaScript image viewer. A list of available features along with corresponding mouse and keyboard actions is shown by pressing 'h'. This method takes the following additional arguments.

`embed`

  logical(1), include images in the document as data URIs. Defaults to `TRUE` in non-interactive context (e.g. static R Markdown documents), otherwise to `FALSE`.

`tempDir`

  character(1), file path for storing any temporary image files. Defaults to `tempfile("")`

`...`

  arguments passed to `createWidget`, such as fixed `width` and `height` (in CSS units), `elementId`, or `preRenderHook`.

### "raster" method

The `"raster"` method displays images as R raster graphics. The user coordinates of the plotting region are set to the image pixel coordinates with the origin `(0, 0)` in the upper left corner.

By default only the first frame of an image stack is shown; a different `frame` can also be specified. When `all=TRUE` the whole image stack is rendered and the frames are automatically positioned next to each other in a grid. The grid layout can be modified through `nx` and `spacing` and `margin`.

This method provides to following additional arguments to `display`.

`interpolate`

  a logical vector (or scalar) indicating whether to apply linear interpolation to the image when drawing.

`frame`

  a numeric indicating the frame number to display; only effective when `all = FALSE`.

`all`

  logical, defaulting to `FALSE`. If set to `TRUE`, all frames of a stacked image are displayed arranged in a grid, otherwise (default) just a single frame specified in `frame` is displayed. The grid layout can be controlled by `nx`, `spacing` and `margin`.

`drawGrid`

  a logical indicating whether to draw grid lines between individual frames. Defaults to `TRUE` unless `spacing` is non-zero. Line color, type and width can be specified through graphical parameters `col`, `lty` and `lwd`, respectively; see `par` for details.

`nx`

  integer. Specifies the number images in a row. Negative numbers are interpreted as the number of images in a column, e.g. use `-1` to display a single row containing all the frames.

`spacing`

  numeric. Specifies the separation between frames as a fraction of frame dimensions (positive numbers <1) or in pixels (numbers >=1). It can be either a single number or a vector of length 2, in which case its elements correspond to the horizontal and vertical spacing, respectively.

`margin`

  numeric. Specifies the outer margins around the image, or a grid of images. Similarly as for `spacing`, different horizontal and vertical margins can be defined by providing a vector.

`...`

  graphical parameters passed to `par`

### Author(s)

Andrzej Oles, andrzej.oles@embl.de, 2012-2017

### See Also

`display-shiny`

### Examples

    ## Display a single image
    x = readImage(system.file("images", "sample-color.png", package="EBImage"))[257:768,,]
    display(x)

    ## Display a thresholded sequence ...
    y = readImage(system.file("images", "sample.png", package="EBImage"))[366:749, 58:441]
    z = lapply(seq(from=0.5, to=5, length=6),
      function(s) gblur(y, s, boundary="replicate")
    )
    z = combine(z)

    ## ... using the interactive viewer ...
    display(z)

    ## ... or using R's build-in raster device
    display(z, method = "raster", all = TRUE)

    ## Display the last frame
    display(z, method = "raster", frame = numberOfFrames(z, type = "render"))

    ## Customize grid appearance
    display(z, method = "raster", all = TRUE,
            nx = 2, spacing = 0.05, margin = 20, bg = "black")

[Package EBImage version 4.20.1 Index]