This disclosure provides methods, devices, and systems for object detection in images. The present implementations more specifically relate to cascaded object detection techniques. In some aspects, an object detection system may obtain a first image and perform a first object detection operation on the first image. The object detection system may select a region of interest (ROI) in the first image based at least in part on the object detection operation, the ROI being selected before the object detection operation is completed. The object detection system may obtain a second image coinciding with the ROI of the first image, the second image having a higher resolution than the first image. The object detection system may selectively perform an inferencing operation on the second image based on a result of the object detection operation.