The watermarking system proposed in this paper offers an expert system technique to help solve the ownership claim on digital images. The watermarking system is based on fuzzy logic and was designed with the intent of embedding watermark features such that they are undetectable to the human visual system. To achieve this objective, the development and design of the watermarking scheme was targeted to utilize three of the five perceptual holes of the human visual system: intensity resolution, intensity sensitivity and spatial masking. Basing the design on these characteristics, the resulting watermarking scheme proved to be resilient to several image processing techniques that are typical for the accidental attack process. The results of the evaluation of the accidental attacks are compared to another spatial watermarking technique. The evaluation of the embedded watermark was subjected to a limited sample of human visual system observers
