in src/api/java/openiss/utils/OpenISSImageDriver.java
lines 137-144 there is logical error
looks like the line 139 should be: int height = image_1.getHeight();
please validate and fix if needed.

below is the original code:

        // check height and width
        int width = image_1.getWidth();
        int height = image_2.getHeight();

        // check equal s

Currently it uses bootstrap 3, which is deprecated. It is necessary to discuss which framework it should use next. Bootstrap 4?