beta.blog

Many of the search results in image searches nowadays spit out images in .webp format. According to Google for Developers, this is the definition:

WebP is a modern image format that provides superior lossless and lossy compression for images on the web. Using WebP, webmasters and web developers can create smaller, richer images that make the web faster. WebP lossless images are 26% smaller in size compared to PNGs.

Although these are displayed correctly in the web browser, they cannot be opened by many other programs. Because of this, here is a small Go program that reads a webp format and converts it to .jpg or .png.

package main

import (
	"image"
	"image/jpeg"
	"image/png"
	"os"
	"path/filepath"
	"fmt"
	_ "golang.org/x/image/webp"
)

func main() {
	if len(os.Args) != 3 {
		fmt.Println("Usage: go run main.go input.webp output.[png|jpg]")
		return
	}

	inputPath := os.Args[1]
	outputPath := os.Args[2]
	outputExt := filepath.Ext(outputPath)

	webpFile, err := os.Open(inputPath)
	if err != nil {
		fmt.Printf("Error opening input file: %v\n", err)
		return
	}
	defer webpFile.Close()

	img, _, err := image.Decode(webpFile)
	if err != nil {
		fmt.Printf("Error decoding WebP file: %v\n", err)
		return
	}

	outputFile, err := os.Create(outputPath)
	if err != nil {
		fmt.Printf("Error creating output file: %v\n", err)
		return
	}
	defer outputFile.Close()

	switch outputExt {
	case ".png":
		err = png.Encode(outputFile, img)
		if err != nil {
			fmt.Printf("Error encoding PNG file: %v\n", err)
		}
	case ".jpg", ".jpeg":
		err = jpeg.Encode(outputFile, img, nil)
		if err != nil {
			fmt.Printf("Error encoding JPEG file: %v\n", err)
		}
	default:
		fmt.Println("Unsupported output format. Please use .png or .jpg/.jpeg")
		return
	}

	fmt.Println("Conversion successful!")
}

To compile simply do:

go get
go build