Which single board computer to choose for image recognition tasks?

Question

Iron

Hello! As part of the graduation project, it is necessary to develop an image recognition system based on a single-board computer.
Vision-based object sorting systems are examples:
Visual object inspection sensor
Orientation detection and quality control
Most likely to be used to recognize the markings of reinforced concrete slabs, and depending on the markings, the geometric size and further sorting will be checked.
Recognition method - contour analysis. There are many articles on habrahabr on this method. Photos will be pulled out of the video stream at the right time.
Recommend a mini computer for this purpose. It is desirable to be able to connect a monitor to control the process. Compact size. I wanted to initially on ARM architecture, but there are too many difficulties. On x86, I considered single-board options (expensive). Also options for motherboards with built-in processor. What is the best choice for these tasks? Suggest your options.
Thank you!