How Software Makes
One Photo Out of Many
We are by now used to the fact that most pictures in our everyday life are not made of solid fields of color and unbroken lines.
They are made up of dots. Take a close look at your computer display or TV, and you’ll see the changing, colored pixels that
create their displays. Even Tim Down’s gorgeous illustrations in this book are—at
their base—collections of colored dots. (Check them with a magnifying glass.)
But the dots here are no more than dots. They are other pictures, photo
mosaics, that are also composites, but composites of other, smaller
photographs. They’re pictures within pictures.
176 PART 3 HOW THE DIGITAL DARKROOM WORKS
One of the best image processors is the human
brain. It’s capable of taking the skimpiest visual infor-
mation and turning it into a larger, more coherent
image. This image, for example, has only 216 pix-
els. But most people can recognize instantly who it is.This example, however,
depends heavily on showing a
well-known person. Most photo
mosaics are not nearly so famil-
iar, but they also have many
more pixels, thousands, that
create a more detailed large
photo, such as this one.2
Using software, photo mosaics can be created in a
matter of minutes on an average PC. The one here,
which consists of 3,600 smaller photos, took ten and
a half minutes to produce on a 3-gigahertz Pentium
4 computer, using AndreaMosaic, which is available
at http://www.andreaplanet.com/andreamosaic/
download/.3
The program divides the
main photo into a number
ofcells, usually the same
size that make up a grid.1 4