Pure golang image resizing
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LICENSE
README.md
converter.go
filters.go
resize.go
resize_test.go
sinc.go
sinc_test.go

README.md

Resize

Image resizing for the Go programming language that includes a few interpolation methods.

Installation

$ go get github.com/nfnt/resize

It's that easy!

Usage

Import package with

import "github.com/nfnt/resize"

Resize creates a scaled image with new dimensions (width, height) using the interpolation function interp. If either width or height is set to 0, it will be set to an aspect ratio preserving value.

resize.Resize(width, height uint, img image.Image, interp resize.InterpolationFunction) image.Image 

The provided interpolation functions are

Sample usage:

package main

import (
	"github.com/nfnt/resize"
	"image/jpeg"
	"log"
	"os"
)

func main() {
	// open "test.jpg"
	file, err := os.Open("test.jpg")
	if err != nil {
		log.Fatal(err)
	}

	// decode jpeg into image.Image
	img, err := jpeg.Decode(file)
	if err != nil {
		log.Fatal(err)
	}
	file.Close()

	// resize to width 1000 using Lanczos resampling
	// and preserve aspect ratio
	m := resize.Resize(1000, 0, img, resize.Lanczos3)

	out, err := os.Create("test_resized.jpg")
	if err != nil {
		log.Fatal(err)
	}
	defer out.Close()

	// write new image to file
	jpeg.Encode(out, m, nil)
}

Downsizing Samples

Downsizing is not as simple as it might look like. Images have to be filtered before they are scaled down, otherwise aliasing might occur. Filtering is highly subjective: Applying too much will blur the whole image, too little will make aliasing become apparent. Resize tries to provide sane defaults that should suffice in most cases.

Artificial sample

Original image Rings


Nearest-Neighbor

Bilinear

Bicubic

Mitchell-Netravali

Lanczos2

Lanczos3

Real-Life sample

Original image
Original


Nearest-Neighbor

Bilinear

Bicubic

Mitchell-Netravali

Lanczos2

Lanczos3

License

Copyright (c) 2012 Jan Schlicht janschlicht@gmail.com Resize is released under an MIT style license.