如何从golang中的url获得图像分辨率

Question

How to get the resolution of an image from a URL in golang.

Below is the code i am trying.

resp, err := http.Get("http://i.imgur.com/Peq1U1u.jpg")
if err != nil {
    // handle error
}
defer resp.Body.Close()

m, _, err := image.Decode(resp.Body)
if err != nil {
    // handle error
}
g := m.Bounds()
fmt.Printf(g.String())

Can you guys tell me how to get the resolution in above situation

Answer 1

You're almost there. Your g variable is of the image.Rectangle type, which has the Dx() and Dy() methods, which give width and height respectively. We can use these to compute the resolution.

package main

import (
    "fmt"
    "image"
    _ "image/gif"
    _ "image/jpeg"
    _ "image/png"
    "log"
    "net/http"
)

func main() {
    resp, err := http.Get("http://i.imgur.com/Peq1U1u.jpg")
    if err != nil {
        log.Fatal(err)
    }
    defer resp.Body.Close()

    m, _, err := image.Decode(resp.Body)
    if err != nil {
        log.Fatal(err)
    }
    g := m.Bounds()

    // Get height and width
    height := g.Dy()
    width := g.Dx()

    // The resolution is height x width
    resolution := height * width

    // Print results
    fmt.Println(resolution, "pixels")
}