pixset {imager}

Pixel sets (pixsets)

Description

Pixel sets represent sets of pixels in images (ROIs, foreground, etc.). From an implementation point of view, they're just a thin layer over arrays of logical values, just like the cimg class is a layer over arrays of numeric values. Pixsets can be turned back into logical arrays, but they come with a number of generic functions that should make your life easier. They are created automatically whenever you run a test on an image (for example im > 0 returns a pixset).

Usage

pixset(x)

Arguments

x

an array of logical values

Examples

#A test on an image returns a pixset
boats > 250
#Pixsets can be combined using the usual Boolean operators
(boats > 230) & (Xc(boats) < width(boats)/2)
#Subset an image using a pixset
boats[boats > 250]
#Turn a pixset into an image
as.cimg(boats > 250)
#Equivalently:
(boats > 250) + 0