Batch-adjusting is as easy as pressing Record in Photoshop!
You simply open the Action-palette, it can be found in the Windows-menu.
Once the palette is open, open the Option-menu in the Palette. Now choose
‘New action’ and name your action - and you’re recording. Go through the steps you
wish (loading Level-presets etc) and hit the Stop-button at the buttom of the
Actions-palette.
Now you’ve got your action down, you need to make into a droplet (which let’s you
drop files on to it). Go to File -> Automate -> Create droplet, work through the
settings and you’re ready to start dropping files on the droplet, and have them
batch converted :-)