Auto-Level Versus Auto-Contrast

[mgilbert]

What is the difference between the Auto-Level and Auto-Contrast commands??? What does each actually do?

[xnview]

'Auto levels' try to expand the histogram of intensity
'Auto contrast' apply brightness/contrast following histogram

[mgilbert]

'Auto levels' try to expand the histogram of intensity
'Auto contrast' apply brightness/contrast following histogram

I understand how auto-contrast works - it finds the brightest and darkest points in a photo, and sets them to a brightness of 0% and 100%

I'm sorry, but I still don't understand what auto-level does. I've never heard of an "intensity' adjustment. Could you explain further?

Thanks...