suggestion for a suitable android device

edit

Computer vision can be very CPU(/GPU)-intensive, so knowing more about your requirements would be helpful. Since most novices don't really know much about what they will be needing, an inexpensive but substantive first SoC can be a good starting point if you are not starting with a higher end i7 or similar. Once you become familiar with the technology and understand your requirements with greater clarity, a more targeted purchase can be made (if needed at all).

If you have a keyboard, mouse, and monitor (or will simply VNC into the platform), you may want to consider an ODROID U3 Community, going for $59 right now. The performance is roughly 25-40% better than the Nexus 7 you have linked (without comparing GPUs). They will also easily fit on mobile platforms like (autonomous) RC cars or quadcopters. http://hardkernel.com/main/products/prdt_info.php?g_code=G138733896281

ODROID quadcopter: http://mil.ufl.edu/propagator/?p=1975

Benchmarks;

• ODROID: http://www.notebookcheck.net/Samsung-Exynos-4412-Quad-ARM-SoC.86876.0.html

• Nexus 7: http://www.notebookcheck.net/NVIDIA-Tegra-3-SoC.72804.0.html

• Graphical comparison of a number of SoCs, including ODROID (see bottom of page); http://iqjar.com/jar/an-overview-and-comparison-of-todays-single-board-micro-computers/