Preview of image database field works just with .png

Question

I can upload images to the server with this code and with the krajee Bootstrap FileInput plugin, but when i try to visualize it, only .png shows an image.

-------------------------Code-------------------------

    var currentFolder = ds.getDataFolder().path+"tmp."+extension; 
    var buffer2 = new Buffer(base64Texto,'base64');
    var vBlob2 = buffer2.toBlob();
    debugger;
    vBlob2.copyTo(currentFolder,"OverWrite")
    var imagen = loadImage(currentFolder);
    archivo.Previsualizacion = imagen;
    archivo.save();

EDIT:

The problem is that when i store the image(.jpg or .pdf) in a image field in the database, preview is blank, but the file from the Blob is well created. With .png it works perfectly.

     var bufferFrom64 = new Buffer(base64Texto,'base64');
     var vBlob2 = bufferFrom64.toBlob(mimeType);
     vBlob2.copyTo(currentFolder,"OverWrite")
     var imagen = loadImage(currentFolder);
     archivo.Previsualizacion = imagen;
     archivo.Documento = vBlob2;
     archivo.save(); 

Answer 1

In short, Wakanda buffer.toBlob() does not play nice with image type especially .jpg or .pdf. .png images have different implementation and will work with toBlob().

This is the code I use to decode images encoded in base64:

   var currentFolder = ds.getDataFolder().path+"tmp."+extension; 
   var bufferFrom64 = new Buffer(base64Texto, "base64");
   var outputFile   = File(currentFolder);
   if(!outputFile.exists)outputFile.create();
   var writestream = BinaryStream(outputFile, "Write");
   writestream.putBuffer(bufferFrom64);
   writestream.flush();
   writestream.close();

Hope it helps.