how to display arduino camera image on tft screen for focusing?

I'm working with several arduino cameras for a couple of projects. I'm also playing with various lenses. As I swap lenses I need to be able to refocus the cameras. Having a screen for the project is not needed, but currently to focus the camera I have to take a series of pictures with incremental adjustments to the lens focus saved to the SD Card and then review them to see if its in focus. It's kind of inaccurate and time consuming. I'm wondering if there's a way to use a tft screen to display images in either real time or from the sd card right after shooting them so I can make adjustments to the focus quicker?

I've got an arduino uno, a ttl serial camera and an arducam mini, and an SD Card datalogging sheild to work with at the moment.

I do not know about the TFT monitor, but I do know that it is VERY difficult to evaluate digitally if a Image is sharp or not. I do not think you will be able to make a sketch that can do that. If you can get it to show up on the monitor, so you can do it manually. Maybe someone else can answer that.

Saying that, bear in mind that my experience with Arduino is very limited, but I do have a lot of experience with digital photography.

Isn't the problem that the "image" from the camera is a JPEG file?