Missing image filename ImageMagick convert running from Node.js only

Question

I built a little script that will first montage 8 tiles together, then scale it down and then it has to distort the image.

Everything goes according to plan until the distorting part.

this.distort = function(filename) {
  var distortDeferred = Q.defer();

  var totalWidth = width * waves * 2,
      totalHeight = height * waves * 2;

  var params = [
    filename,
    '-matte',
    '-virtual-pixel',
    'transparent',
    '-distort',
    'Perspective "{left},{top} {newLeft},{top}   {left},{bottom} {left},{bottom}   {right},{bottom} {right},{bottom}    {right},{top} {newRight},{top}"'.assign({
      left: 0,
      top: 0,
      newLeft: totalWidth * distortPercentage,
      bottom: totalHeight,
      right: totalWidth,
      newRight: totalWidth - totalWidth * distortPercentage
    }),
    filename
  ];

  im.convert(params, function() {
    console.log(arguments);
  });

  return distortDeferred.promise;
};

This following function wil give the error:

Error: Command failed: convert: missing an image filename `tmp/5458f2e3d6840bb65ba6100f.png' @ error/convert.c/ConvertImageCommand/3184.

Running the exact same operation on the command line, will have the desired output.

Possible mistakes I could have made and that I have tested:

• Two image converts, converting the image at the same time
• Non existing image
• File rights to the image are not set correctly
• Missing plugins for ImageMagick

Two image converts, converting the image at the same time

Everything is done with deferreds and promises, so it's not possible that two requests run at the same time, to be sure I set a 2000ms timeout before the distort function was called. Also no help.

Non existing image

Tested this to be sure with a fs.fileExists. Result was as expected.

File rights to the image are not set correctly

To be safe I tried a chmod -R 777 folder on the folder. Result was as expected.

Missing plugins for ImageMagick

After some googling I came across some people that didn't have the appropriate plugins installed and received the same error as me.

Apparently it had something to with either a JPEG library missing or a PNG, see error here.

So after running identify -list format, it was apparent that I have the appropriate libraries installed to complete an operation like this.

Synopsis

I think the error is also probably found in node instead of ImageMagick, because the operation runs from the command line without a problem.