Store Image Variations as Macros

This idea was previously posted as an annotation to another idea.

Many photos might need adjustments such as: brightness, contrast, gamma and saturation. If one makes any adjustments though, he faces several non-ideal choices. He can either:
(a) Keep the original and modified files, using twice the disk space
(b) Keep the modified file and discard the original, and lose some of its information forever since many adjustments aren't completely reversible
(c) Live with the imperfect original photo
(d) Manually modify the imperfect original each time he loads it

Some raster graphics file formats support internal meta data. This includes JPEG, which is the most popular format for photos. It would be very easy to modify an existing image viewer so that it reads any transformation macros stored inside a meta data structure, then apply it to the image as it displays it.
There should be multiple transformations supported for each image. For example, a photo of one's ancestors could viewed as:
* The original
* Optimzed for general appearance
* Optimized for recognition of the people
* Colorized (if black and white)
* With names of the people superimposed
* Several cropped selections
* Several thumbnail sizes
* ...and so on...

Storing all of the transformations listed above as separate files would be a needless waste of space.
One can do something similar in some image editors by recording a macro script which will load and modify a photo for viewing.

Note that a colorized black and white image would be stored in its colorized form, and converted to greyscale when the original is desired. To be certain the original is always recoverable, the software used to colorize it would need to ensure that the average of each RGB triplet was equal to the original greyscale value for that pixel.