I'm getting ready to have my kitchen repainted, and was thinking about trying to smooth out the texture of the walls first. They have a very rough texture, I don't mind some texture, but this is kind of over the top (maybe called halk and trowel texture? Not sure - see picture). I've looked into having it professionally done, but it seems prohibitively expensive.

Anyone know how hard it would be to smooth out the texture? Is there an easy way to do this? If I sand down the bigger bumps, would I need to go over the wall with some kind of joint compound? I don't need it to be completely smooth, just less "hilly."