Since 2D CAD engineering graphics require high precision
a wavelet domain based reversible watermarking algorithm for 2-Dimensional CAD engineering graphics by using improved quantization index modulation (IQIM) is proposed in this paper. First
all vertices in the 2D CAD engineering graphics are extracted
and then Log-polar Mapping and discrete wavelet transform are done to them respectively to achieve the invariance of affine transform. Finally
the encrypted watermark is embedded into detailed coefficients by using improved quantization index modulation (IQIM) scheme. Experimental result shows that the proposed algorithm has a large capacity
good invisibility
and robust against the attacks such as transformation