Quantifying collagen gel contraction is important in tissue engineering and biological research because it provides spatial-temporal assessments of cell behaviors and tissue material properties. However, these assessments currently rely on manual processing, which is time-consuming and subjective to personal opinions. We present a multiresolution image analysis system for automatic quantification of gel contraction. This system includes a color conversion process to normalize and enhance the contrast between gel and background. Then, a deformable circular model is activated automatically to capture details of gel boundaries. These steps are coordinated by a multiresolution strategy. The target measurements are obtained after gel segmentation. Our experiments using 30 images demonstrated a high consistency between the proposed and manual segmentation methods. The system can process large-size images (4000x3000) at a rate of approximately one second per image. It thus serves as a useful tool for analyzing large biological and biomaterial imaging datasets efficiently and objectively.