Golang : Generate thumbnails from images

After learning how to resize images and crop images with Golang. We will learn how to generate thumbnails from images with this excellent image package https://github.com/disintegration/imaging.

The codes below are taken from the https://github.com/disintegration/imaging itself without modification. Please visit https://github.com/disintegration/imaging to know more how to use the imaging package.

 package main

 import (
 "image"
 "image/color"
 "runtime"

 "github.com/disintegration/imaging"
 )

 func main() {
 // use all CPU cores for maximum performance
 runtime.GOMAXPROCS(runtime.NumCPU())

 // input files
 files := []string{"01.jpg", "02.jpg", "03.jpg"}

 // load images and make 100x100 thumbnails of them
 var thumbnails []image.Image
 for _, file := range files {
 img, err := imaging.Open(file)
 if err != nil {
 panic(err)
 }
 thumb := imaging.Thumbnail(img, 100, 100, imaging.CatmullRom)
 thumbnails = append(thumbnails, thumb)
 }

 // create a new blank image
 dst := imaging.New(100*len(thumbnails), 100, color.NRGBA{0, 0, 0, 0})

 // paste thumbnails into the new image side by side
 for i, thumb := range thumbnails {
 dst = imaging.Paste(dst, thumb, image.Pt(i*100, 0))
 }

 // save the combined image to file
 err := imaging.Save(dst, "dst.jpg")
 if err != nil {
 panic(err)
 }
 }

NOTE : The input images varies in sizes and the thumbnails generation function will handle the different sizes.

01.jpg

02.jpg

03.jpg

dst.jpg