A pixel of an image sensor includes only two signal lines per pixel, a pinned photodiode for sensing light, a floating base bipolar transistor, and no reset and address transistors. The floating base bipolar transistor provides the pixel with a gain, which can increase pixel sensitivity and reduce noise. The pixel also incorporates a vertical blooming control structure for an efficient blooming suppression. The output terminals of the pixel are coupled to a common column output line terminated by a special current sensing correlated double sampling circuit, which is used for subtraction of emitter leakage current. Based on this structure, the pixel has high sensitivity, high response uniformity, low noise, reduced size, and efficient layout.