Drupal: larger image on click
I used a combination of colorbox module and insert module. Download and install these modules and the dependency libraries api module. NOTE: on some systems, including mine, only colorbox version 7.x-1.6 worked and not 7.x-2., see also this discussion on drupal.org.
Then download the colorbox plugin (For me only the colorbox master zip worked and not this link. Extract the archive, rename it to "colorbox" and copy it to the path "sites/all/libraries/colorbox", so that it becomes "sites/all/libraries/colorbox/colorbox/jquery.colorbox-min.js".
navigate your browser to
Configuration > Media > ColorBox
I left everything to default.
When writing an article and inserting an image it is necessary to insert the image using the format
colorbox small , colorbox medium or colorbox large
** How to display only the one image you clicked on ** \\