patch_summary_cimg {imager}

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

Description

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

Usage

patch_summary_cimg(im, expr, cx, cy, wx, wy)

Arguments

im

an image

expr

a CImg expression (as a string)

cx

vector of x coordinates for patch centers

cy

vector of y coordinates for patch centers

wx

vector of coordinates for patch width

wy

vector of coordinates for patch height

Examples

#Example: median filtering using patch_summary_cimg
#Center a patch at each pixel
im <- grayscale(boats)
patches <- pixel.grid(im)  %>% dplyr::mutate(w=3,h=3)
#Extract patch summary
out <- dplyr::mutate(patches,med=patch_summary_cimg(im,"ic",x,y,w,h))
as.cimg(out,v.name="med") %>% plot