editing: Image Editing

Description

Read, write and join or combine images. All image functions are vectorized, meaning they operate either on a single frame or a series of frames (e.g. a collage, video, or animation). The Magick++ documentation explains meaning of each function and parameter.

Usage

image_read(path, density = NULL, depth = NULL)
image_write(image, path = NULL, format = NULL, quality = NULL, flatten = FALSE)
image_display(image, animate = TRUE)
image_browse(image, browser = getOption("browser"))
image_append(image, stack = FALSE)
image_average(image)
image_coalesce(image)
image_flatten(image, operator = NULL)
image_fft(image)
image_map(image, map, dither = FALSE)
image_montage(image)
image_morph(image, frames)
image_mosaic(image, operator = NULL)
image_join(...)
image_info(image)
image_animate(image, fps = 10, loop = 0, dispose = c("background", "previous", "none"))

Arguments

path

file path, URL, or raw vector with image data

density

resolution to render pdf or svg

depth

image depth. Must be 8 or 6.

image

object returned by image_read

format

output format such as png, jpeg, gif or pdf. Can also be a bitmap type such as rgba or rgb.

quality

number between 0 and 100 for jpeg quality. Defaults to 75.

flatten

should image be flattened before writing? This also replaces transparency with background color.

animate

support animations in the X11 display

browser

argument passed to browseURL

stack

place images top-to-bottom (TRUE) or left-to-right (FALSE)

operator

string with a composite operator.

map

reference image to map colors from

dither

set TRUE to enable dithering

frames

number of frames to use in output animation

...

images or lists of images to be combined into a image

fps

frames per second

loop

how many times to repeat the animation. Default is infinite.

dispose

frame disposal method. See documentation

Details

Besides these functions also R-base functions such as c(), [, as.list(), as.raster(), rev, length, and print can be used to work with image frames. See transformations for vectorized image manipulation functions such as cutting and applying effects.

Some configurations of ImageMagick++ support reading SVG files but the rendering is not always very pleasing. Better results can be obtained by first rendering svg to a png using the rsvg package.

References

Magick++ Image STL: https://www.imagemagick.org/Magick++/STL.html

Examples

Run this code

# Download image from the web
frink <- image_read("https://jeroenooms.github.io/images/frink.png")
worldcup_frink <- image_fill(frink, "orange", "+100+200", 30000)
image_write(worldcup_frink, "output.png")

# Plot to graphics device via legacy raster format
raster <- as.raster(frink)
par(ask=FALSE)
plot(raster)

# Read bitmap arrays
curl::curl_download("https://www.r-project.org/logo/Rlogo.png", "Rlogo.png")
image_read(png::readPNG("Rlogo.png"))

curl::curl_download("https://jeroenooms.github.io/images/example.webp", "example.webp")
image_read(webp::read_webp("example.webp"))

curl::curl_download("http://jeroenooms.github.io/images/tiger.svg", "tiger.svg")
image_read(rsvg::rsvg("tiger.svg"))
# Create thumbnails from GIF
banana <- image_read("https://jeroenooms.github.io/images/banana.gif")
length(banana)
image_average(banana)
image_flatten(banana)
image_append(banana)
image_append(banana, stack = TRUE)

# Append images together
image_append(image_scale(c(image_append(banana[c(1,3)], stack = TRUE), frink)))
# Combine with another image
logo <- image_read("https://www.r-project.org/logo/Rlogo.png")
oldlogo <- image_read("https://developer.r-project.org/Logo/Rlogo-3.png")

# Create morphing animation
both <- image_scale(c(oldlogo, logo), "400")
image_average(image_crop(both))
image_animate(image_morph(both, 10))
# Basic compositions
image_composite(banana, image_scale(logo, "300"))

# Break down and combine frames
front <- image_scale(banana, "300")
background <- image_scale(logo, "400")
frames <- lapply(as.list(front), function(x) image_flatten(c(background, x)))
image_animate(image_join(frames))