With the increase in the use of technology in controlled environments, a simplertechnique to evaluate plant performance is needed. We developed a non-invasive, quick, and inexpensive image analysis technique to quantify germination rate and seedling vigor. First, we used a chlorophyll fluorescence imaging system where image acquisition and analysis were separate. To automate the process, we integrated embedded computers with a camera in a growth chamber to collect and analyze images from sowing to maturity. To evaluate our tool, we introduced variations by inducing lettuce seeds to saturated salt accelerated aging and NaCl with gibberellic acid (GA3) before sowing. In all studies, we observed a sigmoidal growth curve where plants started slow, increased exponentially, and then plateaued as they matured. Projected canopy size was a good predictor of dry weight using a sigmoidal model (P < 0.001). Our tool performed best with a horizontally structured canopy and limited leaf overlap.