To perform the image processing, high level of computation is needed inside the processor. To perform this task, Raspberry Pi is the only capable of it. You have already done this project, as you have mentioned. If you wish you to stream live display using the camera, you can use Arduino/ NodeMCU. You may not perform the image processing here. If you wish to learn how to stream live display using OV670 Camera Module onto a 1.8-inch TFT LCD screen using Arduino IDE.
you can go for the latest versions of Raspberry Pi- 3, 4 are equipped to process the image processing. The Raspberry Pi 4 is faster and more capable than its predecessors due to the scores of improvements. It can also play 4K video at 60 frames per second.