IMAGING SIGNAL PROCESSING METHODS AND APPARATUS
Methods and apparatus are provided for performing multiple correlated double sampling (CDS) operations on an imaging pixel, and in some cases on an array of imaging pixels, during a single integration cycle of the pixel(s). The multiple CDS operations may produce multiple CDS values, which may be processed in combination to produce a resulting value substantially free of various types of noise. The CDS operations may be performed using a CDS circuit including a single-ended charge amplifier having an input capacitor. The charge amplifier may also include a variable capacitance providing a variable gain. The variable capacitance may be provided by a feedback capacitor.
1 . An apparatus comprising:
an array of MOS imaging pixels comprising a first group of MOS imaging pixels;
a first column line interconnecting the first group of MOS imaging pixels to form a first column of the array, the first column line being configured to receive a pixel output signal from each of the first group of MOS imaging pixels; and
a first correlated double sampling (CDS) circuit comprising a charge amplifier having an input capacitor, the input capacitor of the charge amplifier coupled directly to the first column line to receive the pixel output signals from the first group of MOS imaging pixels.