Abstract:Vehicles powered by diesel engine are widely used in production and transportation because of the excellent power, economy and durability. The environmental pollution caused by diesel cars has been criticized by all sectors of society. The traditional measurement of smoke emission in in-use diesel vehicles by the on-site visual measurement of surveyors is not only affected by surveyors' own state, which leads to inaccurate, but bad for seriously surveyors' physical and mental health. A method of measuring the degree of smoke emission in diesel cars based on machine vision will be proposed. By building hardware measurement platform, using OpenCV as image processing algorithms, and developing VC++ application, the smoke level of diesel cars can be measured in a short time after the experimental verification. It has the characteristics of convenient operation, fast measurement and accurate results.