In some embodiments, an image sensor is provided. A signal processing unit of the image sensor is configured with executable instructions that cause the signal processing unit to perform actions comprising: reading a captured scene from a pixel array; reading a value from a test initiation register; in response to determining that the value indicates a test mode: processing the captured scene to detect a region of interest associated with the value; and providing the region of interest to a first interface for transmission to a host device; and in response to determining that the value does not indicate the test mode: analyzing the captured scene using a computer vision technique to selectively generate a signal based on the analysis of the captured scene; and selectively providing the signal to a second interface for transmission to the host device.