Kodak Digital Learning Center, January 1999
Frequently Asked Questions
http://www.kodak.com/US/en/digital/dlc/book4/chapter1/index.shtml
Contents:
General Questions
1) What are the
advantages of digital pictures?
Since digital cameras take pictures without film or film processing, the
pictures are available for immediate use. Digital pictures can be transmitted
over computer networks, can be stored on a variety of media, and will not
degrade over time (as long as the storage media remains intact).
2) How are digital pictures captured?
The most common ways to capture or make digital pictures are:
Scanning
existing pictures from negatives, slides, or prints, or
Using
a digital camera to take digital pictures.
3) Can my pictures
shot on film be turned into digital pictures for me to use on my computer?
Yes, pictures taken on film are frequently used in the computer environment,
and there are a number of ways to achieve the computer files you need.
Many professional photo labs have taken on the role of service
providers to scan your negatives, slides, or prints (or other flat art) and
provide digital files on KODAK PHOTO CD
Discs. These scans can range in price from less than US$3.00 to
hundreds of dollars depending on the equipment used and the quality needed.
Scans on PHOTO CD Discs provide
high quality and are an excellent source of imagery for computer use.
KODAK
Picture Disk Software, introduced in 1996, provides digital images scanned
from negatives and stored on floppy diskette along with a software program to
view, print and export images to other programs (such as word processing
applications). KODAK Picture Disk Software is available through outlets in the
United States, in particular through retail locations which offer "Kodak
Premium Processing" service. As introduced, KODAK Picture Disk Software,
which comes with each Picture Disk, is compatible with computers using MICROSOFT
WINDOWS Software. KODAK Picture Disk Software is not compatible with APPLE
MACINTOSH Computers. It is possible to view the images on a MACINTOSH computer
using any MACINTOSH program capable of displaying JPEG files.
A variety of photo scanners, including ones for home use, are available to
digitize prints. The KODAK
Snapshot Photo Scanner 1 fits easily on your computer table, no bigger than
a small phone book, and makes it easy to add photos to everything you create on
your computer.
4) What kind of computer system works
best for digital imaging?
Multimedia computers using INTEL PENTIUM, PENTIUM II, PENTIUM III, MIPS or
POWERPC Processors are best for use with digital imaging. However, you can use
many digital scanners and cameras with older computer systems like 386- and
486-based IBM or compatible computers and 68030- and 68040-based APPLE
MACINTOSH Computers provided there is sufficient RAM and disk space available.
5) Which is less expensive, traditional
or digital imaging?
It depends on the application. Small quantities of certain items may be more
economical to produce digitally and large quantities more economical to produce
in the traditional manner, and vice versa. Advances in technology generally
seem to be driving quality up and prices down for many digital imaging
components.
6) What is meant by resolution?
Resolution is the degree of sharpness of an image displayed on a computer
screen or quality of printed output from a laser printer or photo or laser
typesetter expressed in dots per inch (dpi). Resolution can also refer to the
number of bits per pixel. In printing, resolution refers to the space between
dots in a halftone screen and is expressed as lines per inch (lpi).
7) How does resolution affect quality?
Resolution is usually equated with quality. Generally, the higher the
resolution, the higher the perceived image quality.
8) How does resolution affect file
size?
The higher the resolution of the picture, the greater the file size. However,
some image formats like JPEG compress image files so that you can have
high-resolution pictures with relatively small file sizes.
9) What is meant by compression?
Compression is a data storage scheme in which data files are compressed by
algorithms to save disk space.
10) What are software drivers?
Software drivers are files that allow your computer to communicate with a
peripheral device such as a scanner, digital camera, printer, modem, etc.
11) What is a SCSI port? A serial port?
A SCSI port is a place you can connect certain devices like scanners, disk
drives, CD-ROM drives, etc. A serial port is more commonly used for printers,
modems, cameras, etc. Cables are used to connect the ports to the computer.
12) Does a digital camera use film?
A digital camera contains a charge-coupled device (CCD) on which the image is
captured. Software inside the camera looks at the image three times-once each
for red, green, blue-then combines and presents the complete RGB picture on the
screen.
13) Why are digital cameras more costly
than traditional cameras?
In a sense digital cameras are really little computers that can take pictures.
They are packed full of computer memory, microchips, microprocessors, and a CCD
image sensor chip often larger and more expensive than those used in a video
camcorder. However, each new product introduction is decreasing in price and
helping to drive down the cost of digital camera prices.
14) Are the pictures also stored on the
CCD?
No, the CCD is analogous to the film in a traditional camera. The CCD is used
to capture the digital picture. Pictures are usually stored in EPROM (Erasable, PROgrammable Memory) microchips. Some digital
cameras use PCMCIA Cards to store pictures also.
15) Do I have to know a lot about
computers to use a digital camera?
It doesn't hurt, but it's not necessary. The point-and-shoot digital cameras
are geared for the average user, and ease of use is an important part of the
package. The professional digital cameras are aimed at an experienced group of
people who already have solid photographic and computer skills and want
features that take advantage of the advanced equipment.
16) Is there such a thing as "film
speed" with digital photography?
Digital cameras do have "speed" ratings that are similar in concept
to film speed. Some cameras operate at a fixed speed and some offer flexibility
in speeds. What's interesting from a user's point of view is that with some
digital cameras you can change speeds from shot to shot to match changing
conditions. And, much like film, picture quality is usually better when using
slower speed ratings.
17) How many shots will a digital
camera take? Can I erase one if I don't like it?
Digital cameras vary greatly in storage capacity and that's an important
feature to consider when selecting one. In the computer world, memory is a
commodity and it's no different for digital cameras. Some cameras can only
operate tethered to the computer and have no storage of their own. Some have
in-camera storage only, and some have a combination of in-camera storage
augmented by removable memory cards. In all cases, pictures can be
"erased" after they've served their purpose.
18) Can I use digital equipment to make
copies of old family pictures?
The professional digital cameras are excellent for copy work. They operate at a
resolution that is high enough for making sharp copies, and they can reproduce
a wider tonal range than the point-and-shoot digital cameras. The professional
digital cameras can make use of higher quality lenses for that are specifically
designed for copy work. Some of the point-and-shoot, non professional digital
cameras, do offer close-up attachments for use in copying pictures.
You can also scan your pictures into your computer using a photo scanner. The
photo scanner will take a digital picture of your photograph and allow your
computer to display the image.
19) In average use, are digital cameras
affected by high heat and humidity?
Heat and humidity can affect almost anything and digital cameras are no
exception! With many image sensor designs, extreme heat can cause
"noise" buildup, causing the picture to look "grainy"
especially in the shadow or dark areas.
20) When I'm taking pictures, does the
camera always have to be connected to a computer?
Many digital cameras are designed to be used on location and do not need to be
connected to the computer until you want to download or transmit pictures.
21) When the battery
is exhausted, what happens to the pictures I've already taken?
Pictures are stored safely in the camera's memory even if the battery fails or
while changing the battery. They will not be deleted until you instruct the
camera or software to delete the pictures.
22) What is a PCMCIA card?
A PCMCIA* Card is a peripheral device that can add a wide variety of
capabilities to computers including system memory, mass-storage, LAN, fax/modem
and wireless communications. The PCMCIA standardized PC Card is roughly the
dimensions of a thick credit card and has a 68-pin connector at one end. PCMCIA
(Personal Computer Memory Card
International Association ) is a technical design standard and an
international industry trade association.
The PCMCIA interface is a series of hardware and software standards for PC
Cards. These credit-card sized devices can expand the memory, storage,
input/output (I/O), and eventually, the processing capabilities of host
machines. A host machine can be any computer-based device including notebooks,
palmtops, desktop PCs, personal communicators, laser printers, digital cameras,
fax machines, test equipment, and medical imaging equipment.
23) What do the various levels of
PCMCIA cards mean?
To allow manufacturers to add functions and technologies in the PC Card form
factor, PCMCIA has defined three PC Card types. Type I, II, and III cards all
look like credit cards from the top, with the same length and width, but with
different thicknesses. All three have a 3.3-mm thick guide rail around their
edges and connector ends, but Type II and III cards have bubbles or canopies
that are 5 mm (equal to a stack of about 6 credit cards) and 10.5 mm thick
respectively. The guide rails allow the thinner cards to be installed in
thicker slots (for example, Type II cards fit in Type II and III slots, Type I
cards fit in any Type slot).
A Type I PC Card is 3.3 mm thick and is commonly used for system memory
products. Type II PC Cards are 5 mm thick to accommodate applications that
require slightly more room for components such as flash cards, fax/modem, and
network cards. Type III PC Cards are 10.5 mm thick to accommodate
high-functionality products such as rotating disk drives and wireless
communication devices.
24) Do I need to format a PCMCIA card
like I format a diskette?
PCMCIA cards usually are pre-formatted by the manufacturer. They do need to be
formatted for the MS-DOS environment.
II. Storage
1) Where do I keep
my digital pictures after I have looked at them?
Once captured, modified (if necessary), and saved, your pictures are, at this
point, computer files. Just as you need to organize word-processing files or
spreadsheets or database files, now you need to set aside a place for photo
files that you wish to save. You may choose to save them on your computer's hard
drive or you may want to move them to a separate disk or CD-ROM drive.
2) Are digital pictures
"archival"?
Once in digital form on your computer's hard drive, your pictures are
essentially a collection of bits and bytes and, in that sense, they are archival
and they cannot fade or degrade. As long as the storage media remains intact
and there is a device that can replay it, the digital pictures will exist as
you saved them.
3) Can digital pictures be put onto a
PHOTO CD Disc?
Currently, KODAK PHOTO CDPortfolio
II Discs can accept any image files including digital pictures as well as those
from other film scanners or from computer generated files in PICT, TIFF, or BMP
format. Some of the same service
providers who make PHOTO CD Discs also author Portfolio Discs.
4) How much file space does a digital
picture take up? How many pictures can be put on a high density diskette?
File size depends a lot on the camera used to take the picture. A
standard-resolution picture from a KODAK
Digital DC40 Camera takes up about 116 KB, while a picture file from a KODAK
Professional 460 Digital Camera takes up about 18 MB. That's quite a
difference and shows the range in this line of products as well. Approximately
12 standard files created by a Kodak Digital Camera can be written to a
3.5-inch high density floppy diskette.
5) Can digital pictures be compressed?
Using a software package such as PICTUREWORKS PHOTOENHANCER Special Fun Edition
Software, ADOBE PHOTOSHOP Software, etc., you can compress pictures as you save
them. For example, selecting JPEG compression (highest quality), you can
compress a standard-resolution picture from a KODAK
DIGITAL SCIENCE DC20 Camera from about 225 KB to 50 KB and a
high-resolution picture from a Kodak Digital Camera from about 540 KB to 75 KB.
III. Manage
1) What can I do
with digital pictures?
You can do lots of things with the right software...
Using
appropriate software, insert digital pictures into word processing, drawing,
database, or spreadsheet documents for eye-catching and informative reports,
newsletters, brochures, etc.
Send
digital pictures as e-mail attachments over the Internet (more about that in
the section "Share").
Print
digital pictures in color at home on photographic-quality ink-jet paper
products.
Organize
digital pictures into slide and sound shows that replay at the click of a
button.
Make
custom icons and folders and screen savers from them.
You
can even have your digital pictures printed on coffee cups or T-shirts.
2) What is this
"alphabet soup" of file formats-JPEG, GIF, BMP, TIFF, PCD?
A great number of image formats exist because the competition in the software
industry is very intense. Different companies promoted their particular image
format. To make sure their product is useful to a greater number of users,
manufacturers now commonly enable their imaging applications to use a variety
of formats. Each format has a particular advantage.
3) When/why would one save a picture in
JPEG format versus, say, BMP?
Some programs, like word processors, require pictures to be of a certain image
format if you wish to use them in a document. A format like JPEG is simply a
good way to save a high quality picture in a relatively small file; JPEG is
truly cross-platform.
4) What I print out is not the same
color as what I see on my screen. Why is that?
Computer monitors generally can create and display more colors than an ink-jet
printer can for instance. Output that is very different from what is displayed
on screen can indicate that a color management system was not available or not
used. Color management systems are available to help with this problem. Many
are built into operating systems like MICROSOFT WINDOWS 95 Software, APPLE
MACINTOSH OS, and SUN SOLARIS OS. Color management systems help to match what
you see on your display with a particular output device by finding a common
color gamut (range) in which both can work.
5) Can I use my digital pictures in
word processing or database documents?
Yes. Importing digital pictures into newer versions of word processing,
drawing, database, or spreadsheet documents is easy and a very popular feature
of digital imagery. In fact, the quality of pictures taken with point-and-shoot
digital cameras, as well as their ease of use, matches up well with these sort
of applications.
6) Can I add text and graphics to my
digital pictures?
Adding text and graphics to digital pictures is certainly possible. With
software such as PICTUREWORKS PHOTOENHANCER Special Fun Edition, you can
enhance your pictures and easily drop them into personalized templates,
including greeting cards, party invitations, certificates, and awards. If you
are a computer enthusiast, you can add your own text and graphics using
programs such as ADOBE PHOTOSHOP Software and then output to the device of your
choice.
7) Can I edit my pictures? What
software should I use?
One of the great advantages of digital photography is the ability to edit
pictures on screen. Part of the attraction is the fact that it's the modern way
to retouch pictures, and part of it is because it's so much fun! As time
passes, we will see more and more image-editing products enter the market.
Often digital equipment comes with the software packages that provide basic image-editing
tools.
8) Can I use the computer to remove
"red-eye" from my pictures?
You can use your computer along with various image-editing software packages,
to remove red-eye from pictures. PICTUREWORKS PHOTOENHANCER Special Fun Edition
Software allows you to enhance your photos by changing the lighting, focus, or
color saturation allowing you to reduce or eliminate red-eye from your
pictures.
9) Can I adjust the colors in my
digital pictures? How do I do that?
Controls to adjust the color balance of your pictures are included in most
image-editing software packages, such as KODAK Picture Easy and PICTUREWORKS
PHOTOENHANCER Special Fun Edition Software, shipped with point-and-shoot
digital cameras by Kodak.
10) Can I artificially enhance the
resolution of my digital pictures?
You can enhance a picture after it has been captured, but you cannot improve
the actual resolution of the picture. Once the picture has been captured, you
can sharpen it; you can increase its file size (although this interpolates
pixels and does not increase resolution); you can optimize its tonal balance,
remove noise and a host of other modifications, but you cannot improve its true
resolution.
11) Will airport x-ray devices affect
the pictures on my digital camera or storage disks?
Photographers reflexively shy away from airport x-ray devices, but they will
not damage the pictures on your digital camera or storage cards.
IV. Share
1) Can I send my
digital pictures via e-mail over the Internet?
Yes! This is another area where digital pictures shine. KODAK
DIGITAL SCIENCE Picture Postcard Software (available free by downloading
from Kodak's Web site) is an example of a program that allows you to create a
digital postcard and transmit the postcard easily over the Internet. There are
other products and methods for transmitting digital pictures over the Internet
or with online services such as AMERICA ONLINE and COMPUSERVE.
2) Can I make "prints" from
my digital pictures?
You can obtain prints from digital pictures.
Use
a computer printer. The quality and cost of the print depends upon the printer
and the print media you use. Many of the new color ink-jet printers produce
pleasing results, especially if you choose a high quality paper.
The
highest quality results are produced by a thermal dye sublimation printer, such
as the KODAK
DIGITAL SCIENCE 8650 Color Printers. Some service providers offer these
printing options to their customers.
3) Is a copy of a
digital picture as good as the original?
Yes it is. Because the picture actually consists of digital data, copies suffer
no quality loss and are identical to the original.
4) Do digital thermal prints fade over
time?
Thermal prints that are printed using the KODAK
EKTATHERM XTRALIFE Media have been extensively tested for exposure to
daylight and to fluorescent lighting. Under display in typical home
conditions,* we expect prints made with XTRALIFE Media to provide pleasing
pictures for a few generations.
*120 lux for 12 hours per day. Reference:
" A Study of Lighting Conditions Associated with Print Display in
Homes," S. Anderson and R. Anderson, Journal of Imaging Technology, Vol.
17, No. 3, June/July 1991
5) Can I create a digital
"album"? I would like to send a collection of my favorite vacation
pictures to someone I met on our trip.
One way to do this is by using a KODAK DC260 Zoom
Digital Cameras). You can create a custom multi-media slide show from your
digital pictures and save it to a floppy disk (with the SLIDES & SOUND
Projector included). Slide shows saved this way to a floppy disk can
accommodate approximately 20 pictures. (Pictures from sources other than
original digital pictures can also be included.)
6) Can my digital pictures be used with
presentation software packages?
Yes. Once saved, your pictures can be imported into the majority of
presentation packages on the market, for example, MICROSOFT POWERPOINT and
ADOBE PERSUASION Software.
V. Miscellaneous
1) What does digital mean?
Digital refers to the binary representation of data as bits and bytes. The
binary representation of data is basically the language computers use to
create, manage, and store information, music, pictures, etc.
2) What are bits and bytes?
A bit (contraction of binary
digit) is the smallest
unit of information that a computer can store and process. It consists of an on or off
electrical state with a value of zero or one. There are 8 bits in a byte.
3) What is a pixel?
A pixel (contraction of picture element, spelled pixel) is the smallest addressable
point of a bitmapped screen that can be independently assigned color and
intensity. Digital pictures are made from many pixels of varying color and
intensity, much in the same way a mosaic is made from many different colored
tiles.
4) What is a bitmap?
A bitmap is a digital representation of a picture in which all the dots or
pixels making up the picture are rendered in a rectangular grid and correspond to
specifically assigned bits in computer memory.