How to write RIFF chunk header when store image from url? - go

Question

I just tried to download webp image from url, but I found something different when I try to process the stored image.
If I download the image from the browser, it can be decoded using x/image/webp package, but if I store the image using http.Get() then create a new file then io.Copy() the image, it says:
"missing RIFF chunk header"
I assume that I need to write some RIFF chunk header when I store it using golang code.
func main(){
response, e := http.Get(URL)
if e != nil {
log.Fatal(e)
}
defer response.Body.Close()
//open a file for writing
file, err := os.Create('tv.webp')
if err != nil {
log.Fatal(err)
}
defer file.Close()
// Use io.Copy to just dump the response body to the file. This supports huge files
_, err = io.Copy(file, response.Body)
if err != nil {
log.Fatal(err)
}
fmt.Println("Success!")
imgData, err := os.Open("tv.webp")
if err != nil {
fmt.Println(err)
return
}
log.Printf("%+v", imgData)
image, err := webp.Decode(imgData)
if err != nil {
fmt.Println(err)
return
}
fmt.Println(image.Bounds())
}
Here is the URL IMG URL

Answer 1

download file is not webp type. it's png.
package main
import (
"fmt"
"image"
"io"
"log"
"net/http"
"os"
_ "image/png"
)
func main() {
response, e := http.Get("https://www.sony.com/is/image/gwtprod/0abe7672ff4c6cb4a0a4d4cc143fd05b?fmt=png-alpha")
if e != nil {
log.Fatal(e)
}
defer response.Body.Close()
file, err := os.Create("dump")
if err != nil {
log.Fatal(err)
}
defer file.Close()
_, err = io.Copy(file, response.Body)
if err != nil {
log.Fatal(err)
}
fmt.Println("Success!")
imageFile, err := os.Open("dump")
if err != nil {
panic(err)
}
m, name, err := image.Decode(imageFile)
if err != nil {
panic(err)
}
fmt.Println("image type is ", name, m.Bounds())
}