Abstract: Megapixel imagers with computer vision capabilities exhibit high acquisition performance at the expense of a power consumption preventing always-on usage. This paper presents ATIM, a wake-up solution for both 3-scale pattern recognition and motion detection, that is added to a 1360×1120 Global-Shutter commercial CIS without impairing image quality in standard readout modes. ATIM relies on self-adaptation to ambient light conditions, to improve algorithmic robustness for real-world scenarios. This module captures 9 x 9-downsampled 8b images using a dedicated readout and processes 6b 152×112 frames, under an overall power budget of ~450µW at 50fps.