smartcrop

README

smartcrop

smartcrop finds good image crops for arbitrary sizes. It is a pure Go implementation, based on Jonas Wagner's smartcrop.js

Image: https://www.flickr.com/photos/usfwspacific/8182486789 by Washington Dept of Fish and Wildlife, originally licensed under CC-BY-2.0 when the image was imported back in September 2014

Image: https://www.flickr.com/photos/endogamia/5682480447 by Leon F. Cabeiro (N. Feans), licensed under CC-BY-2.0

Installation

Make sure you have a working Go environment (Go 1.4 or higher is required). See the install instructions.

To install smartcrop, simply run:

go get github.com/muesli/smartcrop

To compile it from source:

cd $GOPATH/src/github.com/muesli/smartcrop
go get -u -v
go build && go test -v

Example

package main

import (
	"fmt"
	"image"
	_ "image/png"
	"os"

	"github.com/muesli/smartcrop"
	"github.com/muesli/smartcrop/nfnt"
)

func main() {
	f, _ := os.Open("image.png")
	img, _, _ := image.Decode(f)

	analyzer := smartcrop.NewAnalyzer(nfnt.NewDefaultResizer())
	topCrop, _ := analyzer.FindBestCrop(img, 250, 250)

	// The crop will have the requested aspect ratio, but you need to copy/scale it yourself
	fmt.Printf("Top crop: %+v\n", topCrop)

	type SubImager interface {
		SubImage(r image.Rectangle) image.Image
	}
	croppedimg := img.(SubImager).SubImage(topCrop)
	// ...
}

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

Sample Data

You can find a bunch of test images for the algorithm here.

Development

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

Documentation

Overview

Package smartcrop implements a content aware image cropping library based on Jonas Wagner's smartcrop.js https://github.com/jwagner/smartcrop.js

Package smartcrop implements a content aware image cropping library based on Jonas Wagner's smartcrop.js https://github.com/jwagner/smartcrop.js

Index

• Variables
• type Analyzer
  • func NewAnalyzer(resizer options.Resizer) Analyzer
  • func NewAnalyzerWithLogger(resizer options.Resizer, logger Logger) Analyzer
• type Crop
• type Logger
• type Score

Variables

var (
	// ErrInvalidDimensions gets returned when the supplied dimensions are invalid
	ErrInvalidDimensions = errors.New("Expect either a height or width")
)

Types

type Analyzer

type Analyzer interface {
	FindBestCrop(img image.Image, width, height int) (image.Rectangle, error)
}

Analyzer interface analyzes its struct and returns the best possible crop with the given width and height returns an error if invalid

func NewAnalyzer

func NewAnalyzer(resizer options.Resizer) Analyzer

NewAnalyzer returns a new Analyzer using the given Resizer.

func NewAnalyzerWithLogger

func NewAnalyzerWithLogger(resizer options.Resizer, logger Logger) Analyzer

NewAnalyzerWithLogger returns a new analyzer with the given Resizer and Logger.

type Crop

type Crop struct {
	image.Rectangle
	Score Score
}

Crop contains results

type Logger

type Logger struct {
	DebugMode bool
	Log       *log.Logger
}

Logger contains a logger.

type Score

type Score struct {
	Detail     float64
	Saturation float64
	Skin       float64
}

Score contains values that classify matches