In some examples, a sensor apparatus comprises: an array of pixel cells each including one or more photodiodes configured to generate a charge in response to light, and a charge storage device to convert the charge to output a voltage of an array of voltages, one or more an analog-to-digital converter (ADC) configured the convert the array of voltages to first pixel data, and an on-sensor controller configured to input the first pixel data into a machine-learning model to generate output data comprising prediction data associated with one or more features of the first pixel data, generate, based on the prediction data, second pixel data, the second pixel data associated with one or more transformed features of the first pixel data, and send, from the sensor apparatus to a separate receiving apparatus, the second pixel data.