Imaging Update

When I reviewed the section on how to capture images, it seemed very out of date.

The obvious questions are --

• What has stayed the same?

• What has changed?

The short answer is --

• The technology has improved.

• The principles haven't changed.

• You still need to transform an image into digital data.

You can't do better than to start with digital data.

• In most cases, you start off with a picture or a physical object -- analog data.

• Medical and scientific data often start as digital data.
  • You will actually lose quality by converting the digital image into an (analog) photo and then using your scanner or camera to reconvert the image back into digital format.

Nothing beats silver halide film based photography.

• To quote the June 1997 issue of PC Photo (p. 17),
  • "Traditional film-based photography is still the least expensive way of getting the highest quality images into the computer."
    • Unfortunately, the writer, who was describing an entry level 35 mm camera, didn't say how.

    • However, I will tell you how.

If you have a photo and you need a digital image, scan it into your computer with a flatbed scanner.

Since my last review, scanners have --

• Gone way down in price.

• Gone way up in resolution and color depth capability.
  • Scanners are frequently bundled with image processing and text recognition (OCR) software.

  • Your computer memory or your hard drive or both will need lots of memory first to capture and then to store those humongous graphics files.

There is a major disadvantage of scanners.

• They are confined to digitizing 2-dimensional objects, such as books, photos, paper, etc.

If you use slides instead of prints, you can have a PhotoCD made from the slides or undeveloped slide film.

There are several advantages to this approach --

• The Kodak scanner used to digitize your images is orders of magnitude better and more expensive than anything you are likely to be able to get your hands on.

• The PhotoCD CD ROM is an excellent way to store limited numbers of images, especially if you need multiple resolutions of each.

• Image quality should be excellent.

There are several disadvantages as well --

• The number of images that can be stored in one 650 MB PhotoCD is a little over 100.
  • This is because each image on the PhotoCD is stored at several different resolutions, including a 3k x 2k image appropriate for desktop publishing.

  • Thus, it can be costly to store large numbers of images.

• You might have difficulty finding a local Photo developer able to produce your PhotoCD.
  • PhotoCD's seem less "in vogue" these days.

  • Fortunately, there are mail order houses that will be happy to process your film and return a PhotoCD.

Several photo houses will process your undeveloped film and return a computer disk filled with your images in digital format.

There are several advantages --

• The price and quality are reasonable.

• The service is convenient -- you can often download your images (pictures) from the photo developer's web site!

• Slides and prints can be ordered at the same time.

There are several disadvantages --

• The images may be compressed with a consequent loss of quality.

• The image format used may be an "in-house" variety, unreadable by standard image viewers.

Digital cameras are better than ever. They acquire and store images digitally rather than on film.

Digital cameras deserve their own section. There are many factors involved in choosing one. For now, let us note that ...

There are several advantages

• They are convenient.

• Like a film-based camera but unlike a scanner --
  • They are highly portable.

  • They can "capture" 3-dimensional objects.

• Unlike a film-based camera --
  • Their output is digital (and sometimes video) and immediately viewable and usable in multimedia and Internet applications.

• Their cost and features are making them more attractive.

There are disadvantages --

• Except at the highest price levels, the quality of the images is less -- sometimes much less -- than that produced by inexpensive 35 mm. cameras.
  • This statement could change -- perhaps even in the very near future!

Video capture involves connecting a video device, such as a video camera or VCR, to a computer digitizing board.

The computer digitizing board may be an external box which connects to one of the external computer ports, like Play, Inc.'s popular device, "Snappy," which connects to the PC parallel port.

There are many advantages to video capture --

• Of all the methods discussed here, this is the only one that will allow capture of video from VCR's and TV's in addition to still images.

• As with all cameras, 3-dimensional still images pose no problem.

There are, of course, also disadvantages --

• Resolution is limited to video resolution. There are color limitations as well.

• You are, in general, limited in terms of portability because the video source is physically connected to the computer digitizing device.
  • The old Canon "Xapshot" camera was an exception.
    • Images were stored as analog information on disks which could later be replayed through any video device.

    • Think of the video disks as video tape that can store only one image but could be replayed at any time.

X-rays and other transparencies can be digitized by video capture or by flatbed scanning.

The basic difference between viewing a page in a book and looking at an x-ray is the position of the light source.

• To see (or capture) an x-ray image, we use transmitted light.
  • Thus, to view an x-ray, the light source must be placed behind the radiograph while your eye (or camera) is positioned in front.

  • The same would be needed for any transparency, including media as diverse as photographic slides and stained glass windows.

• To view (or capture) a page from a book, we use reflected light.
  • The light source is placed on the same side as the book.

  • The same approach is needed for viewing any opaque object.

There are specialized digitizing devices with more being created all the time.

You will see digitizing devices specifically made for

• Slides

• Photos

• Documents

• 3-D objects

On the plus side, dedicated digitizing devices are --

• More convenient and/or better suited for their purpose than more generalized scanners, etc.

• Often more expensive

• Definitely less versatile

• Incapable of meeting new needs

Although I haven't emphasized it, getting data into the computer is only the beginning.

Once in the computer the digital data must be

• Image processed

• Output to some device

Image processing is a complex subject.

I'll avoid the subject entirely by stating that --

• There are many software programs available.

• Adobe Photoshop is often regarded as the king of the hill for PC and Mac users.
  • Adobe PhotoDeluxe is --
    • more limited.

    • easier to come to grips with.

    • may very well suit your needs.

• For Amiga users, I can recommend --
  • Art Department Professional (ADPro)

  • Image Engineer (shareware - excellent)

  • ImageFX

• Users of other platforms know to read the appropriate magazines and go to users groups.

Producing the final image is another subject I will avoid. It is too massive a project.

Life is simple for me because --

• I deal in grey scale (x-rays, etc.) images.

• I keep my images in digital format so I can upload them to the Internet.

• My only "hard copies" are the slides I make for my lectures.
  • To make slides, I use my Polaroid CI-3000.

The other major option is prints.

Photographic and computer publications are among your best sources of information.

Most photography and computer magazines have recognized the convergence of the two areas.

Specific magazines you might consult are --

• PC Photo

• Popular Photography

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