readImage {EBImage} | R Documentation |
Functions to read and write images from/to files and URL's. The supported image formats depend on the capabilities of ImageMagick.
readImage(files, colormode) writeImage(x, files, quality = 100)
files |
A character vector of file names or URLs. If missing, an interactive file chooser is displayed. |
x |
An Image object or an array. |
quality |
A numeric, ranging from 1 to 100. Default is 100. |
colormode |
Deprecated. |
When writing images in formats supporting lossy compression (like JPEG),
the quality can be specified used a quality
value in the
range [1,100]
. The best quality is obtained with 100.
The file format is deduced from the file name extension.
ImageMagick
is used to perform all image I/O operations. Therefore,
the package supports all the file types supported by ImageMagick
.
When reading images, files of different formats can be mixed in any sequence, including mixing single 2D images with TIFF image stacks. The result will contain a stack with all images and stacks, at the size of the first image read. Subsequent images are cropped (if larger) or filled with background (if smaller).
readImage
returns a new Image
object.
writeImage
returns invisible(files)
.
Oleg Sklyar, osklyar@ebi.ac.uk, 2005-2006
ImageMagick: http://www.imagemagick.org
## Reads and display images f = system.file("images", "lena-color.png", package="EBImage") x = readImage(f) if (interactive()) display(x) x = readImage(system.file("images", "nuclei.tif", package="EBImage")) if (interactive()) display(x) try({ im = readImage("http://www.google.com/intl/en/images/logo.gif") if (interactive()) display(im) }) ## Converts a TIFF file into JPEG f1 = system.file("images", "lena-color.png", package="EBImage") x1 = readImage(f1) f2 = paste(tempfile(), "jpeg", sep=".") writeImage(x1, f2) cat("Converted '", f1, "' into '", f2, "'.\n", sep='')