even millions of 
ost impossible. 
professional 
for ways to store 
'raphs digitally. 
Photo CD system 
Kodak wanted to 
ch can scan 35 or 
re them efficiently 
; of computer disc 
Photo CD disc 
CD’s) because it is 
, a standard (ISO 
ount of images per 
CD format can be 
, Macintosh, and 
ems provided you 
M reader. 
er methods of 
nputer, Photo CD 
ition (2048x3072) 
ith a large capacity 
either slides or 
ympression format 
image information 
nd decompression 
age compression 
information on the 
ohn Larish (1994) 
s can be displayed 
ha Photo CD 
lia player) and 
ession CD ROM 
Or conversion Or 
> was incorporated 
pression structure 
ans images can be 
julated by users at 
with the proper 
m consists of two 
>m and the user 
system. Film or slide scanning is done in a 
production environment at your local photo 
dealer. This eliminates the need for the user to 
buy expensive scanners, color printers, 
computer workstations, and scanning software. 
It also saves time because the user does not 
have to waste time scanning or maintaining the 
Photo CD scanning computer system. Cost is 
roughly $.65 to $1.50 per slide depending on 
who does your work and how they do it. The 
user system consists of any Macintosh, 
Windows or Unix computer with a multi- 
session CD ROM drive and software to read 
Photo CD (.PCD) format images. To the best 
of my knowledge, Adobe Photoshop, Aldus 
Photostyler, Corel Draw, HiJaak Pro, Kodak 
Photo Edge, Kodak Shoebox, and Kodak 
Access software will read the Photo CD 
format. As with any software, they all have a 
variety of features which may or may not suit 
your needs. 
2.3. Examples 
If I were to hand you two color photo 
enlargements, one made from the original 
slide, the other from the Photo CD disc, you 
could not tell the difference unless you had a 
magnifying glass. That is how good the Photo 
CD system is as compared to other common 
low resolution scanning systems. However, 
due to the nature of this publication, the best 
that can be shown is a camera ready black and 
white copy captured within these proceedings. 
Remember, Photo CD images are much better 
if printed on a full resolution, photo quality 
color printers, not common color inkjet 
printers. 
Figure 1 is an example of a SAC slide 
which has been scanned onto a Photo CD disc 
and printed using a Kodak XL 7700 color 
printer. The image shows this conference’s 
location in the Madison, Wisconsin. North is 
at the top. The University of Wisconsin- 
Madison campus covers the center portion of 
the image. Camp Randall Football Stadium is 
in the left center with the letter “W’ on the east 
and west sides of the seats. Wisconsin’s State 
33 
Capitol is a dark diamond outline of trees 
dominating the isthmus at the right center 
portion of the image between the lakes. The 
ISPRS conference location is halfway between 
the capitol and the stadium on the south shore 
of the large lake at the top of the image. The 
white specs in the water are moored sailboats. 
Memorial Union is just south of the sailboats 
on the south lakeshore. The scale of the 
original slide is roughly 1:120,000. The scale 
of the original Photo CD print used for this 
proceedings is 1:25,000. This slide was taken 
as part of the SAC program. 
Figure 2 is a large scale image of 
Nike's (athletic footware) World Headquarters 
in Beaverton, Oregon. The scale of the 
original Photo CD print used for this 
proceedings is 1:2500. In this case, the photo 
was taken by Aerial Image Technology of 
Portland, Oregon for a demonstration project. 
The interpretation applications of 
scanned images are endless. The author has 
seen many examples from participating field 
offices: identifying saturated soils using slides 
taken during wet years; insuring crop rotation 
patterns are followed from year to year; 
locating old, forgotten drain tiles; finding 
bedrock fracture zones overlaid with glacial 
soil; and so on. In all these cases, the field 
offices have used the off-the-shelf digital 
image manipulation software (such as 
Photoshop) to enhance the original scans to 
highlight features which would normally be 
hidden in the original exposure. 
The most interesting example to date is 
when one of the field office conservationists 
demonstrated the Photo CD system to a 
regional manager from the United States 
Department of Interior. The conservationist 
pulled up a dark, poorly exposed scanned 
aerial slide of the manager's home. After 
running a couple enhancement options from 
Adobe Photoshop, he proceeded to tell the 
regional manager the color and type of roof he 
had on his house; that his driveway was made 
with gravel, and where the deep end of his