Binary CMOS image sensors, methods of operating same, and image processing systems including same

A method of operating a binary complementary metal-oxide-semiconductor (CMOS) image sensor including a pixel array, which includes at least one pixel having a plurality of sub-pixels, the method comprising:

• generating a pixel signal corresponding to sub-pixel signals output from sub-pixels, among the plurality of sub-pixels, activated in response to incident light;
• and
• quantizing the pixel signal based on a comparison between the pixel signal and a reference signal, the pixel signal being indicative of a number of the sub-pixels, from among the plurality of sub-pixels, activated in response to the incident light, and the reference signal corresponding to a threshold number of sub-pixels;
• wherein
• the quantized pixel signal has a first value if the number of sub-pixels activated in response to the incident light is greater than the threshold number of sub-pixels, and
• the quantized pixel signal having a second value if the number of sub-pixels activated in response to the incident light is less than or equal to the threshold number of sub-pixels.

A binary complementary metal-oxide-semiconductor (CMOS) image sensor comprising:

• a readout circuit configured to generate a quantized pixel signal for a pixel having a plurality of sub-pixels based on a comparison between a pixel signal for the pixel and a reference signal, the pixel signal being indicative of a number of sub-pixels, from among the plurality of sub-pixels, activated in response to incident light;
• wherein
• the reference signal corresponds to a threshold number of sub pixels,
• the readout circuit is further configured to generate the quantized pixel signal having a first value if the number of sub-pixels activated in response to the incident light is greater than the threshold number of sub-pixels, and to generate the quantized pixel signal having a second value if the number of sub-pixels activated in response to the incident light is less than or equal to the threshold number of sub-pixels.