stackblur-go

stackblur-go is a Go port of Stackblur algorithm created by Mario Klingemann.

To quote the author this algorithm "is a compromise between Gaussian blur and Box blur, it creates much better looking blurs than Box blur, but it is 7x faster than Gaussian blur."

Comparing to the Javascript implementation the Go version is at least 50% faster (depending on the image size and blur radius), running the same image with the same bluring radius.

Benchmark

Radius	Javascript	Go
20	~15ms	~7.4ms

Installation

First, install Go, set your GOPATH, and make sure $GOPATH/bin is on your PATH.

$ export GOPATH="$HOME/go"
$ export PATH="$PATH:$GOPATH/bin"

Next build the binary file.

$ go get -u github.com/esimov/stackblur-go/cmd

CLI example

The provided CLI example supports the following flags:

$ stackblur --help

Usage of stackblur:
  -gif
    	Output Gif
  -in string
    	Source
  -out string
    	Destination
  -radius int
    	Radius (default 20)

The command below will generate the blurred version of the source image.

$ stackblur -in image/sample.png -out image/output.png -radius 10

To visualize the bluring process the cli command supports the -gif flag, which if set as true it will generate a gif image. For the parallel execution of the the bluring process and the gif visualization goroutines are used. However in case you wish to generate only the blured image, because of API constraints, you need to create a go channel and use this as the last parameter of the Process method. Something like the code below:

var done chan struct{} = make(chan struct{}, *radius)
stackblur.Process(src, uint32(src.Bounds().Dx()), uint32(src.Bounds().Dy()), uint32(*radius), done)
<-done

Original image	Stackblured image

License

This project is under the MIT License. See the LICENSE file for the full license text.