Blur an image — blurImage • recolorize

Blurs an image using the one of five blur functions in imager. Useful for decreasing image noise.

Usage

blurImage(
  img,
  blur_function = c("medianblur", "isoblur", "blur_anisotropic", "boxblur",
    "boxblur_xy"),
  ...,
  plotting = TRUE
)

Arguments

img: An image array, as read in by png::readPNG or readImage.
blur_function: A string matching the name of an imager blur function. One of c("isoblur", "medianblur", "blur_anisotropic", "boxblur", "boxblur_xy").
...: Parameters passed to whichever blur_function is called.
plotting: Logical. Plot the blurred image next to the input for comparison?

Value

An image array of the blurred image.

Details

The parameters passed with the ... argument are specific to each of the five blur functions; see their documentation for what to specify: imager::isoblur, imager::medianblur, imager::boxblur, imager::blur_anisotropic, imager::boxblur_xy. The medianblur and blur_anisotropic functions are best for preserving edges.

Examples

img_path <- system.file("extdata/fulgidissima.png", package = "recolorize")
img <- readImage(img_path)
median_img <- blurImage(img, "medianblur", n = 5, threshold = 0.5)

anisotropic_img <- blurImage(img, "blur_anisotropic",
                             amplitude = 5, sharpness = 0.1)

boxblur_img <- blurImage(img, "boxblur", boxsize = 5)


# save current graphical parameters:
current_par <- graphics::par(no.readonly = TRUE)
graphics::layout(matrix(1:4, nrow = 1))

plotImageArray(img, "original")
plotImageArray(median_img, "median")
plotImageArray(anisotropic_img, "anisotropic")
plotImageArray(boxblur_img, "boxblur")


# and reset:
graphics::par(current_par)