ISO 21227-1:2003 "Paints and varnishes - Evaluation of defects on coating surfaces using Optical inspection imagery, Part 1: General guidance" provides a new method for assessing defects on coating surfaces. The standard aims to provide more objective, accurate and repeatability results by replacing traditional artificial visual assessments with Optical inspection imagery techniques. The standard defines the basic concepts and applications of Optical inspection imagery systems, including relevant terms and methods for image acquisition, processing and analysis. These techniques allow for more precise measurement and evaluation of defects in coatings, especially their performance after exposure to various test conditions (e.g. crushed stone, efflorescence, etc.). This section provides general guidance on quantitative defect assessment using the Optical inspection imagery system. Detailed test methods and accuracy requirements are described in the Miscellaneous section of the standard.