ARM-based Logic Gates Freehand Sketch Recognition

Hand-drawn was concerned by a growing number of researchers in the field of pattern recognition as a direct and simple way of human-computer interaction. And hand-drawn schematic was researched more in recent years as a new direction of circuit design.The circuit design mainly depends on complex softwares such as Protel, Altium Designer, etc. These softwares can only be installed on windows x86systems, and are difficult to achieve on other systems because of high performance requirements.In order to solve this problem, a recognition system that can work on the embedded platform of arm and Linux is designed, the main function of the system is to recognize logic gates circuits. The system gives the user a higher degree of freedom in design circuit. As a real-time system, it can identify the sketch online and display the recognition result immediately.First, users can draw strokes on the touch screen which is connected with the embedded device. The system can extract and store the points, then resample the points, delete noise points by smoothing filter.Secondly, the system extracts feature points of the sample, divides the stroke into several segments according to the number of feature points and classify each segment. It will get a logical group according to the number of feature points, the location and type of the segments. The system compares the group with the template which is built by training and analysing, finds out the classification of the stroke.Finally, the system establishes every stroke recognition result orderly, and then splits out the stroke combination of the logic gates to reconstruct the whole circuit. The system is developed in the environment of Linux RedHat and the development tool is QT4. Experimental results show that the system has a high recognition rate of the logic gates sketch.