Apparatus and methods for generating high dynamic range images

A system, comprising:

• processing circuitry;
• input-output circuitry;
• an array of image sensor pixel that includes a given image pixel having a photodiode configured to generate an image signal in response to incident light, a floating diffusion region, and a transistor interposed between the photodiode and the floating diffusion region;
• and
• a readout circuit coupled to the given image pixel via a pixel output line, wherein the transistor is partially activated during readout operations based on a target swing voltage at the pixel output line and wherein the readout circuit is configured to perform the readout operations on an image readout voltage at the pixel output line corresponding to at least a portion of the image signal and to compare the image readout voltage with the target swing voltage.

An image sensor, comprising:

• an array of image pixels arranged in columns and rows;
• and
• a column readout circuit coupled to each column of image pixels via a column line, wherein the column readout circuit comprises:
• sample and hold circuitry configured to store a reset readout voltage and an image readout voltage;
• residual voltage accumulation circuitry configured to store a sum of residual voltages;
• and
• counter circuitry configured to store a count value.