Angles derived from sets of image pixel values present an effective medium for embedding “invisible” watermarks. The derived angles can be dithered by the addition of small offset angles. The watermark is a pseudo-noise sequence of dither angles. The watermark embedding is followed by re-quantization for image storage of transmission. Watermark recovery is achieved by performing a complex correlation between the watermarked image and the reference pseudo-noise sequence. This occurs without recourse to the original image.This paper analyzes the form of the observed decorrelation as the watermark to image ratio is decreased. The dependence of sequence recovery on 1) the magnitude of the added dithered angle 2) the angle derivation scheme used and 3) on the level of quantization in the original data is discussed.The novel spatially distributed embedding method used here also offers potential robust data encryption advantages.