Auto-levels effect without noise

I want to correct shots I have, the auto-levels give me nice colors and contrast, close to what I remember was in reality, the problem is that it also make a lot of noise in the picture.

How can I create (manually) the changes without getting so much noise?

In the attached picture, the upper version is the original and the second is after auto-levels

As far as I know, you cant. Because When you make the subject better visible, you also make other stuff mor visible.

What I would do:

Use Levels (You get better results when you do it manualy not as autolevels) Use it as a Layer (Layer -> Add Adjustment Layer -> Level) so you can readjust later.

After you are Happy with the results Flatten the Image (Layer -> Flatten Image)

Remove the "big noise" (small fisches etc with the Healing Brush)

Then select only the Shark (maybe using magigc wand or better but more work the path tool) Inverse the selection and use filters on the water to remove the noise (try dust and scratches or Smart Blur) see what has the best effect.

Simon

Or if you want to do it in just a few seconds try 'Filters>Noise>Despeckle'