An image sensor may include an array of image sensor pixels. Each image sensor pixel may have signal storage capabilities implemented through a write-back supply line and a control transistor for the supply line. Each image sensor pixel may output pixel values over column lines to switching circuitry. The switching circuitry may route the pixel values to signal processing circuitry. The signal processing circuitry may perform analog and/or digital processing operations utilizing analog circuits or pinned diode devices for image signal processing on the pixel values to output processed pixel values. The processing circuitry may send the processed pixel values back to the array. This allows the array to act as memory circuitry to support processing operations on processing circuitry in close proximity to the array. Configured this way, signal processing can be performed in close proximity to the array without having to move pixel signals to peripheral processing circuitry.