1. A method for identifying anomalies in an image comprising pixels, the method comprising: subsampling a digital image by a subsample factor related to a first anomaly size scale, thereby generating a subsampled image; smoothing the subsampled image to generate a smoothed image; determining a minimum negative second derivative for each pixel in the smoothed image; determining each pixel having a convex down curvature based on a negative minimum negative second derivative value for the respective pixel; joining each eight-neighbor connected pixels having convex down curvature to identify each initial anomaly area; selecting the initial anomaly areas having strongest convex down curvatures based on a respective maximum negative second derivative for each of the initial anomaly areas; extracting one or more classification features for each selected anomaly area; and classifying the selected anomaly areas based on the extracted one or more classification features.