For this tutorial the mask and image have been sized to 350x350.

Take this image to Image Magick.

Choose the Composite tab.

Enter the Url of this mask.

Now choose "CopyOpacity" from

the Composite dropdown menu.

Click the "Composite" button.

This will be your result...

Now choose the Composite tab again.

Add the Url of this background image.

Choose "DstOver" from the dropdown list.

Check the "Tile across image" box.

Click the "Composite" button.

And presto, here is your new image.

Output and collect your new image.