png or jpg compression | Discord Gophers | Page 1

livid dust Oct 11, 2022, 11:06 AM

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Hey there i'd like to upload some picture on twitter but due to a size limitation i can't so i'd like to compress them a bit. i found this library : https://github.com/h2non/bimg but didn't found any example on how to convert a png to jpg, or just to compress an existing jpg file can someone help me please, this could be using the same library or another one

here is what i got but didn't managed to run it on windows to test it

package main

import (
    "fmt"
    "os"

    "github.com/h2non/bimg"
)

func main() {
    //convert png file to jpg with a quality of 80
    buffer, err := bimg.Read("2371.png")
    if err != nil {
        fmt.Fprintln(os.Stderr, err)
    }

    newImage, err := bimg.NewImage(buffer).Convert(bimg.JPEG)
    if err != nil {
        fmt.Fprintln(os.Stderr, err)
    }

    err = bimg.Write("image.jpg", newImage)
    if err != nil {
        fmt.Fprintln(os.Stderr, err)
    }

}

GitHub

GitHub - h2non/bimg: Go package for fast high-level image processin...

Go package for fast high-level image processing powered by libvips C library - GitHub - h2non/bimg: Go package for fast high-level image processing powered by libvips C library

coarse aurora Oct 11, 2022, 11:18 AM

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You should be able to just post a PNG to Twitter?
How far over the size limit are you?

livid dust Oct 11, 2022, 11:20 AM

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3Mb max from what i saw on github

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just found a way to do it using image library

coarse aurora Oct 11, 2022, 11:20 AM

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Also, reading as PNG and writing as JPEG can be done with the built in img/png and img/jpeg packages, not sure what h2non/bimg does.

livid dust Oct 11, 2022, 11:21 AM

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coarse aurora Also, reading as PNG and writing as JPEG can be done with the built in `img/png`...

yup just found that haha and i don't need to compile other things

coarse aurora Oct 11, 2022, 11:21 AM

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Yes, but how big is the image you're trying to post? If it's 30MB then simply converting to JPEG won't help.

livid dust Oct 11, 2022, 11:21 AM

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oh nope it's like 4 or 5

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but once i convert png to jpeg even with quality set to 100 seems okay

#

package main

import (
    "image"
    "image/jpeg"
    "log"
    "net/http"
    "os"

    _ "image/png"
)

func main() {

    // get image from url
    resp, err := http.Get("url")
    if err != nil {
        log.Fatal(err)
    }

    defer resp.Body.Close()

    // decode image
    img, _, err := image.Decode(resp.Body)
    if err != nil {
        log.Fatal(err)
    }

    // encode image
    f, err := os.Create("image.jpg")
    if err != nil {
        log.Fatal(err)
    }

    // use quality 80
    err = jpeg.Encode(f, img, &jpeg.Options{Quality: 100})
    if err != nil {
        log.Fatal(err)
    }

}