An interactive computer program for seaming a number of images into a panorama. Various parameters which affect how the images are seamed can be changed interactively. Parameters such as position, orientation, focal length, which image will be visible where images overlap, and the opacity curve can be changed. The result of any change is immediately visible. A user can move the control points, thereby "morphing" or distorting the contribution to the panorama of an image. Each pixel is assigned an "alpha" value which indicates the opacity value of that pixel in an area where images overlap. Alpha values can be changed according to a pre-established curve. The original images are not changed. Instead, only the transform between the original images and the final panorama is changed.