images

Images example

This is a small example demonstrating the use of gd. The output in this README is derived from running example.go with gd example.go >README.md.

This comment will be rendered into the Markdown as plain text, Markdown rendering of a C-style comment requires the {md} tag immediately following the /* comment opening.

package main

import (
	"fmt"
	"image"
	"log"
	"net/http"
	"path"

The "show" package is a magic package that is resolved by the gd build tool. The full path may also be used, then it would be "github.com/kortschak/gd/show".

	"show"

Although both jpeg and png input images are being handled by this example, all images are finally rendered as png.

	_ "image/jpeg"
	_ "image/png"
)

var locations = []string{
	"https://blog.golang.org/gopher/glenda.png",
	"https://blog.golang.org/gopher/gopher.png",
	"https://blog.golang.org/gopher/header.jpg",
	"https://blog.golang.org/gopher/404.jpg",
}

func main() {

Each iteration of the loop will be rendered into the Markdown.

	for _, url := range locations {
		resp, err := http.Get(url)
		if err != nil {
			log.Fatal(err)
		}
		img, format, err := image.Decode(resp.Body)
		if err != nil {
			log.Panic(err)

2020/11/01 17:24:37 image: unknown format

panic: image: unknown format

goroutine 1 [running]:
log.Panic(0xc000149f48, 0x1, 0x1)
	/usr/local/go/src/log/log.go:221 +0x10b
main.main()
	example.go:55 +0x1bb

		}
		err = resp.Body.Close()
		if err != nil {
			log.Fatal(err)
		}
		fmt.Printf("The image at %s is a %s.\n", url, format)

The image at https://blog.golang.org/gopher/glenda.png is a png.

The image at https://blog.golang.org/gopher/gopher.png is a png.

The image at https://blog.golang.org/gopher/header.jpg is a jpeg.

		show.PNG(img, url, path.Base(url))

	}
}