Kodak M575 has a
14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Kodak M381 has a
12.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor .
Below you can see the M575 and M381 sensor size comparison.
Kodak M575 and Kodak M381 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.