smartcrop.go

smartcrop implementation in Go

smartcrop finds good crops for arbitrary images and crop sizes, based on Jonas Wagner's smartcrop.js

Image: https://www.flickr.com/photos/usfwspacific/8182486789 CC BY U.S. Fish & Wildlife

Installation

Make sure you have a working Go environment. See the install instructions.

Additionally you need to have opencv installed.

You can install it on Mac OS X using:

brew tap homebrew/science
brew install opencv

On Linux you need to have the following packages installed:

libcv-dev libopencv-dev libopencv-contrib-dev libhighgui-dev libopencv-photo-dev libopencv-imgproc-dev libopencv-stitching-dev libopencv-superres-dev libopencv-ts-dev libopencv-videostab-dev 

Now you can install smartcrop, simply run:

go get github.com/muesli/smartcrop

To compile it from source:

git clone git://github.com/muesli/smartcrop.git
cd smartcrop && go build && go test -v

Example

package main

import (
	"github.com/muesli/smartcrop"
	"fmt"
	"image"
	_ "image/png"
	"os"
)

func main() {
  fi,err := os.Open("test.png")
  if err != nil {
    log.Fatalf(err.Error())
  }

  defer fi.Close()

  img, _, err := image.Decode(fi)
  if err != nil {
    log.Fatalf(err.Error())
  }

  analyzer := smartcrop.NewAnalyzer()
	topCrop, _ := analyzer.FindBestCrop(img, 250, 250)
	fmt.Printf("Top crop: %+v\n", topCrop)
}

With face detection:

func main() {
  fi,err := os.Open("test.png")
  if err != nil {
    log.Fatalf(err.Error())
  }

  defer fi.Close()

  img, _, err := image.Decode(fi)
  if err != nil {
    log.Fatalf(err.Error())
  }

  settings := smartcrop.CropSettings{
    FaceDetection:                    true,
    FaceDetectionHaarCascadeFilepath: "./files/aarcascade_frontalface_alt.xml",
  }
  analyzer := smartcrop.NewAnalyzerWithCropSettings(settings)
  topCrop, _ := analyzer.FindBestCrop(img, 250, 250)
  fmt.Printf("Top crop: %+v\n", topCrop)
}

Also see the test-cases in crop_test.go for further working examples.

Development

API docs can be found here.

Join us on IRC: irc.freenode.net/#smartcrop

Continuous integration: