This invention implements a system for automatic recognition of human-assisted drawings, in a plurality of forms, be they hand-drawn on paper, marker board, with a stylus on a computer, made with a mouse, stylus, finger or other instrument on a personal computer, tablet computer, smart telephone or other medium. At the core of the invention is a pattern recognition engine, aimed at recognizing the graphical objects, handwritten text, equations or interconnects in the input image, and interpreting the significance of their relative association. The apparatus offers error correction, vector representation of the input sketch, as intermediate output, along with the recognized patterns, arranged in a hierarchical data structure, ready to be passed on for mining or assessment. The recognized patterns can be associated with mechanical design, electrical circuit design, mathematics, biology, physics, chemistry, computer science, natural sciences, medicine, or any other science- or engineering-based discipline making use of human-assisted drawings.