An imaging system includes a row and column array of active pixels, each having an associated pitch. In response to respective control signals, each pixel outputs a reset level which includes noise components, or a signal level which includes signal and noise components. Multiple column buffers, each having a pitch equal to or less than that of a pixel, convey the outputs of respective pixel columns to a bus line. Each buffer comprises ‘odd’ and ‘even’ S&H/CDS circuits, which process the pixel outputs of odd and even rows, respectively. Each S&H/CDS circuit subtracts pixel reset level from signal level to produce an output in which correlated noise is suppressed. Each column buffer includes a buffer amplifier which conveys the output to the bus line. A gain amplifier separate from the column buffers is coupled to the bus line such that it amplifies the outputs of a multiple column buffers.