All images are loaded (including ones that aren't used in the current script)

When starting up, all image files in the image directory are loaded into memory.

```
image_paths = os.listdir(IMG_DIR)
images = {path.split(".")[0]: load_image(path) for path in image_paths}
```

This makes startup slower, produces irrelevant logs and will grow as a problem if more image files are added to the repo.

Solution:
When starting up a script, only image files referenced in that script should be loaded.