dhash: calculation of the 'dhash' of an image

Description Usage Arguments Details Value Examples

View source: R/hash_functions.R

Description

This function calculates the dhash of an image

Usage

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dhash(gray_image, hash_size = 8, MODE = "hash", resize = "nearest")

Arguments

gray_image

a (2-dimensional) matrix or data frame

hash_size

an integer specifying the hash size (should be less than number of rows or columns of the gray_image)

MODE

one of 'hash' (returns the hash of the image), 'binary' (returns binary identifier of the image)

resize

corresponds to one of 'nearest', 'bilinear'

Details

The function is a modification of the 'dhash' function of the imagehash package [ please consult the COPYRIGHT file ]. In comparison to average_hash and phash, the dhash algorithm takes into consideration the difference between adjacent pixels.

Value

either a hash-string or a binary vector

Examples

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image = readImage(system.file("tmp_images", "3.jpeg", package = "OpenImageR"))

image = rgb_2gray(image)

res_hash = dhash(image, hash_size = 8, MODE = 'hash')

res_binary = dhash(image, hash_size = 8, MODE = 'binary')

OpenImageR documentation built on Sept. 10, 2021, 5:08 p.m.