go-imageresizer

README

Go-ImageResizer

Introduction

This program is meant to load a directory of JPEG images, and serve them as either JPEG or WEBP, with three different quality settings. This is mostly mean to be used on a web server to deliver smaller images to mobile devices, and also quickly load light previews of the images.

Installation

To install, run:

got get github.com/chai2010/webp
go get github.com/nfnt/resize
go get github.com/BurntSushi/toml
git clone https://github.com/Neirpyc/Go-ImageResizer
cd Go-ImageResizer
go build *.go -o imageResizer
./imageResizer

Configuration

Setting are provided in the file settings.toml. Here is an example:

port="8000"
cacheFolder="/tmp/cache_imageResizer"
inputFolder="/var/www/images/"
maxCacheSize="500MB"
logFile="log.log"
preCache=true

• port: The local port on which the program will listen.
• cacheFolder: The folder in which served images will be cached.
• inputFolder: The folder in which served images will be fetched.
• MaxCacheSiwe: Should be in b, B, Kb, KB, Mb, MB, Gb or GB. It represents the maximal size the cache folder will use.
• logFile: Path of a file in which logs will be stored.
• preCache: should be true or false
  • true means the program will on launch rescale the all images in the input folder and pre-cache them.
  • false means nothing will be done on launch.

Examples

Examples assume you use the previously shown config file.

The following request: localhost:8000/images/lod/2/holidays/sunset.webp will seek for /var/www/images/holidays/sunset.jpg and return it, converted to webp, and scaled according to the constants defined in main.go:19, which are by default: 250px width, encoding quality of 65, and height scaled appropriately to keep aspect ratio.

const (
	Lod1Width       = 40
	Lod1Quality     = 40
	Lod2Width       = 250
	Lod2Quality     = 65
	Lod3JpegQuality = 70
	Lod3WebpQuality = 80
	Lod3SmallWidth  = 450
	Lod3MediumWidth = 820
)

If the file has already been served by the server, it is likely it'll be in the cache, and will be found and sent without rescaling the image another time.

Here are a few request examples:

• localhost:8000/images/lod/1/holidays/sunset.webp
• localhost:8000/images/lod/2/holidays/sunset.webp
• localhost:8000/images/lod/2/holidays/sunset.jpg
• localhost:8000/images/lod/3/small/holidays/sunset.webp
• localhost:8000/images/lod/3/medium/holidays/sunset.jpg
• localhost:8000/images/lod/3/big/holidays/sunset.jpg

Demo

A live demo can be found here.

license

This program is licensed under the GNU GPL v3 license. Please see the LICENSE file for details.