CMPLX synthesizes a complex image from a real and a imaginary buffers.
IMAG extracts the imaginary part of a complex image.
REAL extracts the real part of a complex image.
CONJ take the complex conjugate of the complex image.
The 'source' buffer does not have to be a complex image for commands IMAG, REAL and CONJ to operate. If the 'source' image is not complex, REAL will extract the odd columns, IMAG will extract the even rows, and CONJ will simply multiply the even columns by -1.