Set the similarity of the images you want to find here.
Note that 'Exact Match' finds exact pixel duplicates of the images (ignoring tags). The other settings compare for similar images, ignoring colour and tags (unless you specify a tag)
Notes:
If you just want to compare image tags, and ignore the actual image, you can select 'Ignore'.
For very small resolution files such as small icons, exact matching may produce better results
If you are getting false matches, try unchecking the 'Find Rotated' and 'Find Flipped' settings, and lock the search to 'Same Resolution' and 'Same Aspect Ratio' settings. Also try increasing the similarity.
All Similar modes (not Exact Match) use colour-insensitive matching (greyscale).
This option groups the images by geo-location, within a user specified radius. The location is taken from the image tags (Lattitude/Longitude). The image must contain location tags for this to work - this is supported by most modern cameras and smartphones if enabled.