Introduction

Mouseover Popup Image Viewer (MPIV) is a userscript that shows images and videos behind links and thumbnails. Its features include:

Installation

Install & Discuss @ GreasyFork

How to Use

ActionTrigger
open popupmove mouse cursor over thumbnail
close popupmove cursor off thumbnail, click, zoom out fully, ...
suppress/freeze popuphold down shift while entering/leaving thumbnail
force popup (ignore size threshold)   hold down ctrl while entering image element
activate zoomright-click or tap shift while popup is visible
adjust zoommouse wheel up/down to zoom in/out
flip through album (e.g. imgur)mouse wheel, j/k or left/right keys
open file in new tabpress "t" while popup is visible
download filepress "d" while popup is visible (Firefox and Chrome)
change settingsmonkey toolbar icon -> "User Script Commands" -> "Set up..."

Notes