Face Detection Sometimes Doesn't Work until I send to Viewer and run Face Detect

[kiwilink]

Sometimes when I am in my Category panel I will select a single or multiple images and right click and choose Face recognition.  I pick Default size, it says  file(s)  added to background and when I look at the Info and Activity panel or the bottom right I don't see any activity.  I then go check the log and search for the file name and I don't find any errors (see attachment, File 7679).  

I then send the image to the viewer and choose face recognition and it works every time.  Any idea what would cause this?  I attached a zip of the log in debugging mode after I sent it to the Viewer and it worked.


Thanks!

Kiwilink

[kiwilink]

This post is not referring to 2025.  I ran into this before I upgraded.  I did not check it after the upgrade.

[Mario]

This is easy to explain: The faces are to small.

When you use the "Default" setting and not the "Optimize for small faces" setting, IMatch may not be able to detect the faces in the small image it uses in this case.

If you run it later in the Viewer, IMatch uses the full-size (cache) image and the faces then are large enough to detect. This is slower, though.

If faces are not detected with the "Default" settings, just run it again with the "Optimize for small faces" option.
I have designed this this way since using a large image makes face recognition 4, 8, or 16 times slower, depending on the ratio between the original image size and the smaller size IMatch uses for face recognition by default.

The default is able to find faces in typical family & friends and portrait photos. If you process images with many people (sport teams, choirs, ...) or images where persons are distant from the camera and their faces are small, use the Optimize..." mode.

[kiwilink]

Yes, that fixed it.  Thx!