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Visual quality of watermarking for mobile devices

Abstract— In this study, the visual quality of watermarked images, displayed on mobile devices, are evaluated. A watermarking technique in the spatial domain where a watermark is embedded into an image is considered. Three different types of images are considered and for each image five values of watermarking magnitude were tested. The difference in human evaluation of visual quality of a watermarked image, depending upon image properties and the properties of a display was evaluated. In visual assessment tests, images from a mobile phone, PDA, and CRT were used. The visual quality of watermarked image was evaluated by 20 human observers. The results were quantified using statistical testing. The results show that for high‐end displays the magnitude used for watermarking is a critical factor in image quality. In mobile devices the magnitude used for watermarking has little visual effect, especially for technical drawings. Recommendations for proper parameters are given.