accumimage and accumcolor are packages for the Go programming language that provide the ability to accumulate and average colors. accumcolor.AccumNRGBA is the accumulating analogue of the Go standard library's color.NRGBA (a single pixel of non-alpha-premultiplied red, green, blue, and alpha channels), and accumimage.AccumNRGBA is the accumulating analogue of the Go standard library's image.NRGBA (a 2-D array of NRGBA pixels).
In addition to three color channels and an alpha channel, an accumcolor.AccumNRGBA contains a tally of the number of colors that have been added together. The Add method adds another color to the existing one, both weighted by their tally. The NRGBA method divides each channel by the tally to produce an ordinary color.NRGBA.
accumimage and accumcolor can be useful for blending multiple overlapping images, for mapping a large number of pixels to a smaller number (e.g., when scaling an image), and for distinguishing pixels in an image that are truly empty (e.g., unvisited in an algorithm that visits all pixels) from pixels that have a color, even one that is fully transparent.
Assuming you are using the Go module system, simply import accumimage and accumimage/accumcolor:
import (
"github.com/spakin/accumimage"
"github.com/spakin/accumimage/accumcolor"
)Then run go mod tidy to download and install the package files.
See the pkg.go.dev documentation for accumimage and accumcolor.