Method and apparatus for reducing temporal row-wise noise in imagers

A readout circuit for a pixel array, comprising:

• a sample and hold circuit comprising:
• a noise reference storage area switchably coupled to a noise reference source for storing a noise reference;
• and
• a pixel storage area for storing pixel signals from a column of the array;
• and
• first and second storage areas in the pixel storage area for storing charge accumulation and reset signals from a pixel;
• and
• a noise reference signal storage area comprising third and fourth storage areas for storing first and second noise reference signals from a noise reference source, wherein a first side of the third storage area is switchably coupled to a first side of the fourth storage area and the noise reference source, a second side of the third storage area is switchably coupled to a first input of the amplifier, and a second side of the fourth storage area is switchably coupled to a second input of the amplifier.