Thumbnailer

Thumbnailer is a simple utility library and CLI for generating image thumbnails, written in Golang.

It's heavily inspired by prplecake/go-thumbnail, with some additional functionality and adjusted ergonomics.

Usage

As a library

To install Thumbnailer as a library, go get it:

go get github.com/jordanfitz/thumbnailer

Then, you might make use of the library like this:

package main

import "github.com/jordanfitz/thumbnailer"

func main() {
    inputData, _ := os.ReadFile("input-image.jpg")

    t := thumbnailer.New().
        With(thumbnailer.OutFormat(thumbnailer.JPG)). // output a JPG
        With(thumbnailer.Quality(50)).                // encode the JPG with quality 50
        With(thumbnailer.MaxSize(200)).               // don't let the thumbnail exceed 200px, width or height
        With(thumbnailer.Image(inputData))            // use inputData as the source image

    outputData, _ := t.Create()

    // do something with outputData
    // ...
}

As a command-line utility

To install the CLI, run go install:

go install github.com/jordanfitz/thumbnailer/cmd/thumbnailer@latest

Then, use the utility like this:

# generate thumbnails for all PNG files in my-images/, outputting
# JPG files with a quality of 50 into the directory my-images/thumbs/
thumbnailer my-images/*.png -o jpg -q 50 -o my-images/thumbs

More information can be gleaned from thumbnailer -h.