Pixpipejs

This does the following :

opening a distant image (1) file with AJAX request, using pixpipe.UrlImageReader
opening another distant image (2) file with AJAX request, using pixpipe.UrlImageReader
(image 1 and image 2 have the same size and same number of band)
use image 2 as a mask and blend both using a pixpipe.ImageBlendExpressionFilter
displaying the final output in a canvas using pixpipe.CanvasImageWriter

Note that using a parametric math expression with pixpipe.ImageBlendExpressionFilter is generally slower.

The original image and the mask:

The blended image, only the lighter parts of the second images are visible: