Can anyone help to solve the strange image problem?

Hello all,

I found a strange problem of ofImage:
After system recognized the people face,
I captured the face into a color ofImage
object and check all pixels value are normal,
but, it will appear abnormal values after
draw it. Can anyone help to solve this?
thanks!

source code(face_capture.zip) link–>
http://www.mediafire.com/?5s0c817697v11a2

kaykay