Opencv (JavaScript) Mat from Array doesn't work

Question

I'm trying to create a mat from an 2d array using the cv.matFromArray(rows, cols, type, array); method.

It works with really small arrays like this:

  let mat = cv.matFromArray(2, 2, cv.CV_8UC1, [255, 255, 128, 128]);
  return mat; // works

But when i basically do the same thing with my image array (1024x1024px, values range from 20 to 230) it just fills every Mat value to 0

const mat = cv.matFromArray(img_array.length, img_array[0].length, cv.CV_8UC1, img_array);
return mat; // every value is 0

Why is that?

Answer 1

Okay, I converted the 2d array to 1d like this:

[].concat(...img_array);

and its working now:

img_array; // 1024x1024px 2d array

const mat = cv.matFromArray(img_array.length, img_array[0].length, cv.CV_8UC1, [].concat(...img_array));
return mat;