System and method for image aspect preservation in multiple projector alignment

A method is disclosed herein that derives a post-alignment transform that is applied to the input source after the application of an alignment transform to ensure that when each source illuminates the screen, the display is aligned and retains the correct displayed aspect ratio. The transform takes into account the alignment transform and the input source aspect, and then performs a secondary, post-processing transformation that corrects the distortion induced by the alignment transform. This aspect-preserving function is a linear transform that maps pixels in the aligned space to the aligned and aspect-correct space and can be applied to the input signal after the first alignment transform, or, in the case where the alignment transform is also linear, transforms can be directly combined to derive a compound multi-projector, aspect preserving transform. In this way, the input signal to the projectors will be aligned as well as retain proper aspect.