combining two images with different ratios

[Twitty27342513lmn9]

how to combine(morph /blend /mix) two faces in different ratios like :30-70 (30 %from face 1 and 70 %from face 2), 40-60, 50 - 50 etc.

like image attached below...

[Mylenium]

There's all kinds of software for this, but this is nothing you can do in an automated fashion Photoshop. Manipulating official document photos as per your example is illegal, anyway. If you werte to do something liek this in PS you'd have to use the Puppet Tool, Liquify etc., but it's all manual work and you can't really control the mix ratios that precisely.

Mylenium