IMAGE PROCESSING APPARATUS, IMAGE PROCESSING METHOD, IMAGE PICKUP APPARATUS, ON-BOARD SYSTEM, AND MOVABLE APPARATUS

An image processing apparatus includes a memory storing instructions, and a processor configured to execute the instructions to generate, using a first image obtained by imaging a three-dimensional space including an object through an optical system of a first projection method, a second image obtained by a second projection method different from the first projection method, and perform object detection using the second image. A distortion ratio on the second image satisfies a predetermined condition.