Convert a base64 string encoded image to a tiff format in javascript

Question

I have a base64 image that I need to convert into a .tiff format. Is there a (pure) javascript way to do it please ?

NB : I saw base64 encoding was just a compress of the original file, I did this to recover the original file but now have to transform it to tiff

function urltoFile(url, filename, mimeType){
    mimeType = mimeType || (url.match(/^data:([^;]+);/)||'')[1];
    return (fetch(url)
        .then(function(res){return res.arrayBuffer();})
        .then(function(buf){return new File([buf], filename, {type:mimeType});})
    );
}

Answer 1

The framework I use (CEP) allow to convert local file into tiff format using this code :

//save the file in tiff format in a specified fodler
csInterface.evalScript(`exportFile()`, function(path) {
     console.log("saved at",path);
});

//in jsx 
function exportFile() {
    Folder((fnp = (aD = activeDocument).fullName.parent + '/folder/')).create();
    aD.saveAs(File(fnp + aD.name), new TiffSaveOptions(), true, Extension.LOWERCASE);
    return activeDocument.fullName;
}


//then u can get it with this code
 csInterface.evalScript('app.documents[0].fullName.fsName', function(res) {
      //give the location of the current document
      let path = res;
      path  = res.substring(0, res.lastIndexOf("\\"));
      let fileName = res.substring(res.lastIndexOf("\\"));
      fileName = fileName.substr(1, fileName.lastIndexOf(".")) + "tif";
      path += "\\folder\\" + fileName;
      console.log(path);

      let fileInBase64 = window.cep.fs.readFile(path, cep.encoding.Base64);
      //transform the path to match the tif file
      //let fileName =  res.split('\\').pop().split('/').pop();
      urltoFile('data:image/png;base64,'+fileInBase64.data, fileName)
      .then(function(file){
        console.log(file);
      });
});