Panograph Joiner Images

A "panograph" is the name given to the process of manually combining mulitple photographs to form a single image, generally a wider field of view image. The style originated in the 1970s and was popularised by a David Hockney after gluing multiple polaroid photographs together. Hockney coined the name "joiner" to the result. In the era of digital photography the technique has become commonly called a panograph, a combination of of the terms panorama and photography. Unlike the panorama where one generally attempts to create a seamless result, as if the result were a single photograph itself, the panograph is used in reference to the manual and intentionally imperfect formation of an image from a series of photographs. The imperfections can include exposure differences, transparency differences, and geometric alignment errors.

Like the photography for a panorama, one takes a number of photographs of a scene. Each image should/might have some overlap with it's neighbours. Given that the photographs, without warping, cannot seamlessly form a wide angle result, a joiner image is an artistic rendition of the scene. As such, it is common practice to also take the photographs at random angles.

Unlike panorama stitching where an attempt is made to remove any evidence of the process, in a joiner image the individual photographs are made explicit and discontinuities in the objects in the scene are intentional.

Exhibition building, Melbourne.

Since joiner images are often (but not necessarily) taken from a single camera location, to reduce parallax effects, they can usually be perfectly stitched using conventional panorama stitching software. Since wide fields of view are often involved, in this case the individual images are have been warped and mapped onto a cylindrical panorama or equirectangular projection. In addition, the images can be colour matched and blended between the image patches.

Perfect warp/blend using traditional panorama stitching techniques.

As an intermediate approach, feature points can be found between the photographs in order to derive their optimal placement. The relative opacity and colour corrections can be performed manually to give the desired visual effect.

Feature points for automatic photograph placement.

Unlike panorama photography where a perfect seamless result is the goal, there are few rules for a joiner image. The above examples used automatic camera exposure, the following have fixed exposure so there is an even lighting between the photographs. The different patches are made visible by vaying the transparency.

Parliament of Victoria, Melbourne.

When placing each photograph in the collage it is common practice to do so with each photograph at 50% transparency, this is illustrated in the following. The field of view in this example is about 220 degrees, hence the extreme geometric distortion. The imperfect alignment also arises from taking the photographs from different locations.

St Patrick's cathedral, Melbourne.

In summary there are a number of techniques to control how clean or messy the final image appears. These include: taking the photographs at different locations, choosing random camera angles, using manual or automatic exposure, varying the layer order for the photographs and varying the transparency of each photograph.

It is possible to create a simulation of a panograph using a single image. This can be achieved by repeated copy/paste from the single image to the panograph and adding transparency and rotations.

Pou Tai Un Temple, Macau