Change image contrast — contrast.img • trackter

Changes the contrast of an image or images

contrast.img(img = NULL, c = 2, out.dir = NULL, type = NULL)

Arguments

img: character, a path to an image file or directory containing images.
c: numeric, the factor by which to change the contrast. 'c'>1 enhances, 'c'<1 reduces.
out.dir: character, the directory to which the image will be saved.
type: character, image type (optional). Must be: "jpeg", "png", or "tiff (case ignored)." If missing, file format is automatically determined by file name extension(s).

Examples



#retrieve image in system
 y <-system.file("extdata/img", "sunfish_BCF.jpg", package = "trackter")
od <- paste0(tempdir(),"/cropimg")
dir.create(od)

#display original
EBImage::display(EBImage::readImage(y),method="raster")



# adjust contrast and save as original format
contrast.img(img=y,c=0.5,out.dir=od)

#display modified image
EBImage::display(EBImage::readImage(paste0(od,"/sunfish_BCF.jpg")),method="raster")


#clean up
unlink(od,recursive=TRUE)