A wavelet watermarking technique combined with fractal coding is proposed. First

a host image is partitioned into a set of non-overlapping square blocks. These blocks are sorted to become a descending sequence according to their collage errors which are obtained by performing baseline fractal coding

and two equal-length subsequences are chosen respectively according to the watermark size. Second

the watermark

which is first scrambled using arnold transform

is embedded into low-frequency bands in wavelet domains of distinct blocks in the two selected subsequences by a new embedding formula. Last

the watermark is the fusion of the extracted watermarks from the two selected subsequences. The experimental results show that this technique achieves good perceptual invisibility and security

and is also very robust against some image processing such as cropping

adding noise

scribbling

filtering

rotation and JPEG compression.