Comparison of CDMA Watermark Techniques in Spatial Domain and Wavelet Domain on Digital Images

Abstract

Presentation of data and information has been progressing quite rapidly, so data and information has been widely presented in digital format. Problems began to emerge as widespread digital data need to be protected. This is related to ownership, copyright, or authenticity issues. This study tries to provide solutions to these problems by applying the digital watermarking with Code Division Multiple Access (CDMA) technique. This technique uses a digital image composed of a cover image and two types of watermark (initial and copyright). There are two stages in this research, the first is trying to insert two types of watermark on the cover image in two different domains, namely spatial domain and wavelet domain. Once inserted, the watermark is extracted back to be compared with the original watermark. The second is attempting to insert an initial watermark on the cover image in two different domains, then giving some distortion of the image to be tested for resistance. After that, the watermark is extracted again. From the experiment results, it is known that wavelet domain CDMA is superior in terms of quality of the extracted watermark, processing time, and resistance to distortion (JPEG compression and gamma correction). While CDMA coding spatial domain is simpler and has a resistance to gamma correction only.