Computer
Info –
This Week’s Program
Let’s take a look at scanning slides
and negatives. We will be using our
Epson 1250P (a low end priced scanner) to demonstrate this.
Scanners
– More than you want to know
(
http://www.pctechguide.com/18scanners.htm )
Interpolation
Scanners
typically offer resolutions of 2,400dpi, 4,800dpi and 9,600dpi. Its important to realize that scanners simply aren't capable
of picking up this level of detail. The actual optical resolution of the CCDs in most modern scanners is 600 x 1,200dpi at best and
all higher figures are based on interpolation.
Note
that the specification of a non-uniform resolution - for example, 600 x 1200dpi
- necessarily implies hardware interpolation, since the acquisition of data at
600dpi in one axis and 1200dpi in the other clearly cannot result in a
"square" of data. At 600 x
600dpi such a scanner will interpolate the 1200dpi dimension down to 600dpi
(usually done by merely running the stepper motor that moves the light bar at
twice its minimum rate), or at 1200 x 1200dpi they interpolate up the x
dimension. Basically, an integrated
circuit chip in the scanner generates new data by taking the dots the scanner
actually sees, and calculating where the dots in-between would most likely
fall, using an algorithm to "guess" the colour
of the new dots by averaging the colour of adjacent
dots.
Software
interpolation can increase the resolution even more than hardware
interpolation. It is performed by the PC's processor under the control of the
scanner's TWAIN driver software. The problem is that best guesses can never be
truly accurate. Interpolated images will always seem too smooth and slightly
out of focus. This doesn't matter so much with line-art where interpolation has
the effect of smoothing out jagged edges. But for continuous-tone images like
photographs its often better to stick with a scanner's
actual optical resolution.
Color
Most
modern color scanners are at least 24-bit, meaning that they collect 8 bits of
information about each of the primary scanning colors: red, blue, and green. A
24-bit unit can theoretically capture over 16 million different colors, though
in practice the number is usually quite smaller. This is near-photographic
quality, and is therefore commonly referred to as "true color"
scanning.
Recently,
an increasing number of manufacturers are offering 30-bit and 36-bit scanners
capable, so they claim, of producing better quality color images. Whilst the
fact is that very few graphics software packages are capable of handling images
with more than 24 bits, the additional bits are still worth having. When a
software program opens a 30-bit or 36-bit image, it can use the extra data to
correct for noise in the scanning process and other problems that hurt the
quality of the scan. With more inherent information present in 30- and 36-bit
scanned images, users can more precisely alter image detail and RGB luminance
values via the scanner's driver software.
TWAIN
TWAIN
allows software applications to work with image acquisition devices without
knowing anything about the device itself. If a device is TWAIN compliant and a
software application is TWAIN compliant, the two should work together
regardless of whether or not the software was bundled with the image
acquisition device when it was purchased.
OCR
Recent
OCR technology is far more sophisticated than the early techniques. Instead of
just trying to identify individual characters, modern techniques are able to
identify whole words. This technology, developed by Caere,
is called Predictive Optical Word Recognition (POWR).
Using
higher levels of contextual analysis, POWR is able to virtually eliminate the
problems caused by noise. It enables the computer to sift through the thousands
or millions of different ways that dots in a word can be assembled into
characters. Each possible interpretation is then assigned a probability, and
the highest one is selected. POWR uses
sophisticated mathematical algorithms which allow the computer to hone in on
the best interpretation without examining each possible version individually.
HP ScanJet 5490Cse
This
full-featured unit has won raves from reviewers like Smart Computing and ZDNet.
The latter likes the 5490Cse for its 2400 x 2400 dpi resolution
and software bundle, while Smart Computing, which includes this ScanJet on its top-five list, says it’s “an easy-to-use
flatbed scanner with results that really don’t require much adjusting. The HP
has an auto-feed tray for making multiple copies, as well as an included transparency
adapter for scanning slides and negatives. Experts say this is the model to get
if you want professional-quality scans of your color photos.
This
scanner lists for around $375.
http://www.consumersearch.com/www/computers/scanners/
Epson 1250P
This
is a low end scanner – but does a good job for the price. The P at the end of the scanner model
indicates that the TPU (transparency unit) is included.
This
scanner has an optical resolution of 1200x1200.
As
with all scanners, it comes with a TWAIN driver. Therefore you can start your scan from any
photo-editing software. The first time
you try to use the TWAIN driver from a software program,
you will have to select the scanner
that you want to scan with. In the case
of this scanner, you would select the EPSON TWAIN. It is best to have it default to the MANUAL
mode, rather than the AUTOMATIC mode.
This way you have the ability to adjust various settings – such as SCANNING
SLIDES – SCANNING NEGATIVES – SCANNING PHOTOS – choose the RESOLUTION – click
on the PREVIEW button so that you can select the area that you want to scan.
The
better your original, the better the scan will be.
Where is the Clipboard Viewer in Windows XP
by Andy Rathbone,
author of Windows XP For Dummies
When
you highlight something in Windows and choose Copy, nothing happens. Sure,
you've copied something to the Windows Clipboard, ready to be pasted into
another program. But how do you know? How
can you tell exactly what you've copied?
In
earlier versions of Windows, you could simply call up the Clipboard Viewer.
That handy little program promptly showed you the Clipboard's contents,
providing visual assurance that you've copied the correct item. In fact, by
leaving the Clipboard Viewer open on your desktop, you could easily watch the
Viewer refresh its display to reflect your newly copied material.
But
for some reason, Windows XP messed up the Clipboard Viewer, a Windows staple
for more than a decade. The Viewer is barely mentioned on XP's Help menus, and
although it's supposedly installed automatically when you upgrade to Windows
XP, it doesn't appear on any menu.
And that's a shame, because the Viewer is a
handy way to keep track of exactly what's on your clipboard during an
action-packed cut/paste session. Here's what happened.
First,
Windows XP's Clipboard Viewer is now called the Clipbook
Viewer. And although XP places the program on your hard drive, here's how to
place the Clipbook Viewer's icon onto your Start
menu:
1. Click the START
menu button and open MY COMPUTER.
2. Open your C
drive. (It's listed in the Hard Disk Drives section.)
3. Double-click
on the Windows folder. (You might have to tell it to let you see
what's inside.)
4. Double-click
on the SYSTEM32 folder. (Again, you might have to tell it to let you
see what's inside.)
5. Scroll down
the page until you locate a file named Clipbrd.
6. Drag and drop the Clipbrd file onto your Start button.
Just
let go of your mouse button when it's pointing at the Start button; that drops
a shortcut to the Clipbook Viewer onto your START
menu. When you open your START menu, the Clipbrd program's
icon will appear near the top. (Feel free to right-click the clipbrd's icon, choose RENAME, and type in
Clipbook Viewer. If you're angry at XP,
rename it Clipboard Viewer, just out of spite.)
Whenever
you want to see exactly what's being stored on your Clipboard, double-click
that icon. The Clipbook Viewer appears, letting you
see exactly what's been cut or copied to your Clipboard.
Sulfnbk.exe (a hoax – not a virus)
If
you receive an email message like this one – telling you that you have a virus –
PLEASE CHECK IT OUT. Remember, McAfee
and Norton are in the business of detecting viruses – so why is it that your friends
know about a virus and how to remove it when McAfee and Norton don’t?????
The
email message will contain information similar to this ------ “received a virus
via email that is automatically transmitted via address
books. Because I have your address it
means you're likely to
have it. Supposedly the virus is not detected by
McAfee or Norton, and lies dormant for 14 days or more before it closes down
your entire system. My anti-virus
program did not detect it. I have
located the file and deleted it from my computer per the instructions. You should do the same. It is very easy to do.
To
remove the virus use the following:
1. Go to "Start" and click
2. Click on "find or search"
3. In the "search
for files or folders" type in "sulfnbk.exe". This is the virus
4. In the "look in" make sure you are
searching drive C:
5. Click on the "search" or
"find" button
6. If you have the virus it will have an ugly
blackish icon that will have the name
"sulfnbk.exe" DO NOT OPEN.
7. Right click on the file and go down to
"delete" and left click on it.
8. Send to recycle bin
9. Exit out and go to desktop where the
"recycle bin" icon shows and double click.
10. Right click on Sulfnbk.exe and delete again
or empty the recycle bin.
If
you find this virus, send these instructions to everyone in your address book,
because they now have it and it is transmitted from your address book. It has a mind of its own.”
AGAIN, I AM NOT TELLING YOU TO
FOLLOW THE ABOVE INSTRUCTIONS. PLEASE
READ AGAIN THE FIRST PARAGRAPH OF THIS ARTICLE.
CHECK WITH MCAFEE, NORTON, OR A GOOD SEARCH ENGINE
TO VERIFY BEFORE FOLLOWING THIS INSTURCTIONS OR PASSING THIS INFORMATION ON.
The
Sulfnbk.exe file is not required to run Windows. It may be necessary if you
need to restore long file names if the file names become corrupted. For
additional information, read the Microsoft Knowledge Base article Description
of Sulfnbk.exe and How to Replace the Program File (Q301316)