Is it possible to convert base64 image format?-CodePudding

Issue description:

I'm currently working on Ionic 6 / Capacitor / Angular 12 application. I'm using the giving @capacitor/camera plugin Who return me some base64 images (with getPhoto function).

If the user take directly photo from the device the function would return me JPEG base64 image.

But if user take photo from the library, I can get any other format as image (png, gif ...) and that cause issue in my case.

Because my backend want work only with JPEG files.

I already checked:

png-to-jpeg — package seem old/deprecated, I wasn't find any solution with it, and have npm medium and critical issue (so I ll skip it).
jimp — package seem to be what I need but cannot find any thread or example matching my problem.

Questions:

Did anyone know if it possible to convert image png to jpeg from base64 ?
If 'yes' — can it possible in Javascript and how ?
Else — Do you have any alternative alternative ?

CodePudding user response：

You can do it by changing the media type in the base64 string. The base64 string consists of the following:

data:[<mediatype>][;base64],<data>

So if you could change

data:image/png...

data:image/jpeg...

it should work fine. Whenever you will be creating a image to download, it will choose the bits in accordance with the lossless compression to generate a jpeg for you

CodePudding user response：

You may try sharp like below

const sharp = require("sharp");

async function convert() {
  try {
    await sharp("myfile.png")
      .toFormat("jpeg", { mozjpeg: true })
      .toFile("smyfile.jpeg");
  } catch (error) {
    console.log(error);
  }
}