Although the dominant seismic data processing are still based on the acoustic wave assumption, the elastic wave processing and imaging are more and more popular in recent years. A major challenge in elastic wave processing is the shear-wave model building. For this reason, a sequence of procedures for estimating seismic shear-wave velocities and the subsequent generation of seismic images using converted-waves are introduced. The PS-wave images produced by this technology could be aligned with the PP-wave images such that both can be produced in the same coordinate system without any squeezing or stretching. The registration between PP and PS images provides cross-validation of the migrated structures and better estimation of underground rock and fluid properties. There are mainly two essential new supporting techniques in this work: the first one is decoupling of the S-wave information by generating common focus point (CFP) gathers via applying the P-wave velocity on the converted seismic data; and the second one is to pick an optimal VP/VS ratio on the newly proposed semblance spectrum. The S-wave velocity, computed from the picked optimal ratio, can be used not only for generating the PS-wave images, but also to ensure well registration between the converted-wave and P-wave images.