pairwise_comparison: Compare a pair of images

In EQUALCompareImages: Comparison of Images for Researchers Without Coding Skills

Compare a pair of images

Description

This is the main function of this package and supports both the compare_similarities_two_images() function and the compare_similarities_same_image() function.

Usage

pairwise_comparison(image_1, image_2, 
include_dimension_insensitive_measures = FALSE, remove_dominant_colour = FALSE,
extra_parameters = "")

Arguments

image_1	The first image of the pair of images for which the comparison must be made.
image_2	The second image of the pair of images for which the comparison must be made.
include_dimension_insensitive_measures	Logical (default value is FALSE) indicating whether dimension insensitive measures such as perceptual hash must be calculated. These are necessary only for the comparison of images without any modification as these measures are expected to find similarities between the images even if they are rotated or resized.
remove_dominant_colour	Logical (default value is TRUE) indicating whether the dominant colour must be removed. When indicated as TRUE, this is performed only for the comparison of images without any modification as some of the algorithms to find similarities between the images even if they are rotated or resized rely on the background colour.
extra_parameters	By default, only absolute error and perceptual hash are calculated and reported. Measures such as fuzz, root mean squared error can also be calculated optionally.

Value

a data frame containing the pixels_compared, absolute_error, perceptual_hash, and any optional measures.

Note

This is part of a suite of functions required to compare images.

Author(s)

Kurinchi Gurusamy

References

https://sites.google.com/view/equal-group/home

See Also

compare_similarities_two_images() compare_similarities_same_image() find_dominant_colour()

Examples

# Create a plot and save this as file
filename_1 <- tempfile(fileext = ".png")
png(filename_1)
plot.new()
hist(rnorm(100))
recordPlot()
dev.off()
# One more plot for comparison
filename_2 <- tempfile(fileext = ".png")
png(filename_2)
plot.new()
boxplot(rnorm(100))
recordPlot()
dev.off()

# Read images
library(magick)
image_1 <- image_read(filename_1)
image_2 <- image_read(filename_2)

# Perform the function
results <- pairwise_comparison(image_1 = image_1, image_2 = image_2, 
                               include_dimension_insensitive_measures = TRUE)

EQUALCompareImages documentation built on Sept. 9, 2025, 5:35 p.m.