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imager (version 1.0.5)

Image Processing Library Based on 'CImg'

Description

Fast image processing for images in up to 4 dimensions (two spatial dimensions, one time/depth dimension, one colour dimension). Provides most traditional image processing tools (filtering, morphology, transformations, etc.) as well as various functions for easily analysing image data using R. The package wraps 'CImg', , a simple, modern C++ library for image processing.

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Install

install.packages('imager')

Monthly Downloads

6,643

Version

1.0.5

License

LGPL-3

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Repository

https://github.com/asgr/imager/

Homepage

https://asgr.github.io/imager/

Maintainer

Aaron Robotham

Last Published

August 2nd, 2025

Functions in imager (1.0.5)

as.data.frame.pixset

Methods to convert pixsets to various objects

Find the boundary of a shape in a pixel set

Photograph of sailing boats from Kodak set

blur_anisotropic

Blur image anisotropically, in an edge-preserving way.

Blur image with a box filter (square window)

Control CImg's parallelisation

Convert cimg to spatstat im object

Add circles to plot

Capture the current R plot device as a cimg image

Canny edge detector

Clean up and fill in pixel sets (morphological opening and closing)

Fill in a colour in an area given by a pixset

Various useful pixsets

Blur image with a box filter.

Display image using CImg library

cimg.dimensions

Image dimensions

Various shortcuts for extracting colour channels, frames, etc

Display image list using CImg library

Return contours of image/pixset

Split a video into separate frames

Return pixel values in a neighbourhood defined by a stencil

Coordinates from pixel index

Return coordinates of subset of pixels

Flatten alpha channel

Erode/dilate image by a structuring element.

Compute image gradient.

Crop the outer margins of an image

Concatenation for image lists

Correlation/convolution of image by filter

Create a cimg object

Center stencil at a location

Split a colour image into a list of separate channels

distance_transform

Compute Euclidean distance function to a specified value.

Circle detection using Hough transform

Highlight pixel set on image

Grayscale dimensions of image

Compute Haar multiscale wavelet transform.

Apply recursive Deriche filter.

Return image hessian.

extract_patches

Extract image patches and return a list

Display object using CImg library

Split an image along axis, apply function, return a list

Draw rectangle on image

Split an image, apply function, recombine the results as an image

Estimate displacement field between two images.

diffusion_tensors

Compute field of diffusion tensors for edge-preserving smoothing.

Evaluation in an image context

Draw circle on image

Draw image on another image

Coordinates as images

Split an image along axis, map function, return a data.frame

imager: an R library for image processing, based on CImg

Check that value is in a range

Hough transform for lines

Split an image along a certain axis (producing a list)

Select image regions interactively

Draw text on an image

Colour space conversions in imager

Grow/shrink a pixel set

Combining images

Create an image of custom size by filling in repeated values

Convert an RGB image to grayscale

Generates a "dirac" image, i.e. with all values set to 0 except one.

Shift image content.

Generate (Gaussian) white-noise image

Combine a list of images into a single image

Modify parts of an image

Replace part of an image with another

Array subset operator for cimg objects

Linear index in internal vector from pixel coordinates

Mirror image content along specified axis

Blur image with the median filter. In a window of size n x n centered at pixel (x,y), compute median pixel value over the window. Optionally, ignore values that are too far from the value at current pixel.

Permute image axes

Select part of an image

Return image patch summary

Split an image along a certain axis (producing a list)

Compute image gradient

Compute the periodic part of an image, using the periodic/smooth decomposition of Moisan (2011)

Check that an object is a pixset object

Plot objects on image using base graphics

Pixel sets (pixsets)

Load image from file or URL

Replicate images

Load example image

Rotate an image along the XY plane.

Check that an object is an imlist object

Return the pixel grid for an image

Checks that an object is a cimg object

Interpolate image values

Fill-in NA values in an image

Convert a magick image to a cimg image or image list and vice versa

Load a video using ffmpeg

Renormalise image

Type-stable map for use with the purrr package

Make/save a video using ffmpeg

Build simple interactive interfaces using imager

Remove empty dimensions from an array

split_connected

Split pixset into connected components

Label connected components.

Return information on image file

Apply function to each element of a list, then combine the result as an image by appending along specified axis

Blur image isotropically.

Compute image hessian.

Compute image Laplacian

Display an image using base graphics

Pad image with n pixels along specified axis

Mutate a data frame by adding new or replacing existing columns.

Rotate image by an arbitrary angle, around a center point.

patch_summary_cimg

Extract a numerical summary from image patches, using CImg's mini-language Experimental feature.

resize_doubleXY

Resize image uniformly

Plot a line, Hesse normal form parameterisation

Plot an image list

Select a region of homogeneous colour

Load all images in a directory

Threshold grayscale image

A pixset for NA values

px.remove_outer

Remove all connected regions that touch image boundaries

A cross-shaped stencil

Young-Van Vliet recursive Gaussian filter.

Remove alpha channel and store as attribute

Compute watershed transform.

Return locations in pixel set

as.data.frame.cimg

Convert a pixel image to a data.frame

Turn an numeric array into a cimg object

Add colour channels to a grayscale image or pixel set

Compute the Discrete Fourier Transform of an image

as.cimg.data.frame

Create an image from a data.frame

Convert a raster object to a cimg object

as.cimg.function

Create an image by sampling a function

Convert a RasterLayer/RasterBrick to a cimg image/image list

Convert to cimg object

Convert an image in spatstat format to an image in cimg format

Compute the bounding box of a pixset

Convert a cimg object to a raster object for plotting

Convert various objects to image lists

Return or set pixel value at coordinates

Methods to convert various objects to pixsets

as.data.frame.imlist

Convert image list to data.frame

Autocrop image region

as.igraph.pixset

Form an adjacency graph from a pixset

Form a graph from an image