PC Plus HelpDesk - issue 260
Remove ugly orphans
your HTML pages, you sometimes get single words at the
end of a paragraph and want to make sure that these
orphans never exist, here's how to do it.
Orphans can make a paragraph look quite ugly. In
effect, all you need is a way of tying together the last
word and the penultimate word so that they never
Fortunately, this can be done quite easily. All you
need to do is to open up the html page in your favourite
text editor. Find the end of each paragraph by opening
the search (usually [Ctrl][F]) and looking for
'</p>', '</li>' or '</td>' (this will
find most instances of end of paragraphs).
In between the last two words, replace the space with
' ' which is an HTML escape character that
represents a 'No-Break SPace'. (HTML escape
characters start with an ampersand and finish off with a
The ' ' character will force the last two
words to appear together on the same line.
You can see in the screenshot that in the web page
(lower half) that there is enough space for the word
'either' but, because it is 'glued' to the word 'end', it
is forced to appear on the next line.
Once you have edited your file, save it as plain text
with the same file name.
Snooping IT staff
A recent survey revealed that roughly one in three IT
admin staff abuse their privileges by snooping around
ordinary user's confidential data such as private files
and emails, wages and even your data from the personnel
You cannot stop them because they need to have that
type of access should you have a genuine problem.
However, you can encourage such abuse to present
itself from which point it can be dealt with by the
There is a counter-intelligence technique called
'barium meal'. Real Barium Meal (a suspension of Barium
Sulphate) is impervious to x-rays and therefore, when
present inside an otherwise invisible container - such as
your gut - it can reveal the shape of thing such as the
container itself or any foreign objects in there. In the
image on the right, you can see that it has revealed an
obstruction or a narrowing.
In effect, it
reveals the presence of a hidden structure.
|So, how do we reveal the existence of a path
between our suspected insecure source (our personal
account or details on our system) and something,
We need to know the rules so that we
can plant something there that will reveal that they have
been broken. For example, confidential information must
be confidential. So, if we plant something there and it
appears somewhere else, we know that somebody has broken
the rules (possibly even the Law - Computer Misuse Act,
Data Protection Act and so on) and with any luck, the
trace back from where it appeared will reveal the
So, we need a way of differentiating between our
information and all of the other legitimate traffic.
- Legitimate traffic is caused by reality so one
way of differentiating between our traffic and
reality is to make it contain false information -
preferably a high proportion of false
- One problem with false information is is that if
it is too far away from what could happen, it
will not be believed so, it also has to be
- Finally, remember that we are using it to
identify the person that took it and we cannot do
that if it is in a number of places so, it has to
Essentially, that is it - it has to be unique,
plausible but false and you can put it in one place such
as a file. If the information ever appears anywhere else,
you know that there is a connection between where you put
it and where it appeared.
|If you make the carrot extra tasty, you are
more likely to get a result.
- An example could be a false email where you claim
to have lied on your CV about your qualifications
although you need to make sure that you can find
your certificates first;
- Another could be false information about a senior
- Another could be an orchestrated conversation on
the telephone between you and someone else who is
in on it. You arrange it so that you both have
the same script (passed person to person or some
other secure way) and then you play it out over
the telephone; and so on.
One thing you need to be, though, is patient.
On the right, you can see that a directory is
protected so that only the user has access. In this way,
the only other person that has access is someone with
root privileges. When they su to root, they can look at
and open the files. In that way, if that information ever
shows up anywhere you know that it was somebody with root
privileges. One thing that you could do with this is to
change the data every now and then so that it pin-points
a time period.
Wilf Hey and I had some fun with this in the 1990s.
All good fun - for us.
Controlling USB devices
On a Linux
system, you can plug your camera into your Linux box and
it mounts all right under KDE. However, you might find
unmounting it a bit more of a problem and, if you have
written to that device, it is best to unmount it rather
than just unplug it. So, how do you make it flush its
cache before it loses contact?
When you plug in a USB storage device - whether that
is a camera or just an SD card or similar block storage
device - a KDE daemon opens up a dialogue box that gives
you a number of options. The default is 'Open in a New
Window'. Pressing [Enter] opens this but removing it
safely is a different matter.
So what about the other end of the process -
|If you haven't got the little camera icons
in the panel as in the screenshot, right-click on the
panel and select 'Panel Menu', 'Add Applet to
Panel...'and then, in the dialogue box that appears,
scroll down to and click on 'Storage Media' and then
click on 'Add to Panel'.
|A camera icon will appear in the panel for
each USB block device and a floppy if you have one.
to remove it properly, just left-click on the icon and
then on 'Safely Remove'.
Whereis, Whatis, Apropos
Knowing the name of a program and knowing what it does
are always a problem, no matter which operating system
you use and whether you use a GUI or a command line.
So, here are some ways out of problems on two
UNIX-like systems - Linux (SuSE 10.2) and OpenBSD.
a program called?
|We know that we've
installed a browser on the system but we can't
remember what it is called.
The solution is to
use the apropos
command, along with a keyword such as, in this
only remember how the program name starts. How do
I find the rest of its name?
|If you are using the
Bash prompt, all you do is type the first few
characters, then press [Tab]
twice - it will beep at you the
seen another program in that list. How do I find
out what it does?
|If you know the name
of a program and you want to find out what it
does without loading the full manual, just use
to know where a program that I can use from the
bash prompt is.
|If you need to know
where just the program is, you can use the which
to know where a program and related files such as
binary source and manual pages are located
|To find the location
of these files as well as the actual binary, in
Linux, use the whereis
command. This command in OpenBSD acts the same as
to look up details of the program in the manual
|The manual shows you
a lot of information about a program. Originally,
these were the way that a systems administrator
refreshed his knowledge of a program. More
recently, other ways such as info pages and so on
have been used and on some systems the man pages
have been neglected to some extent. However, if
you are on a text-only terminal, these are a good
way of finding out more as they don't need a GUI
to work. If you want a GUI, open up Konqueror and
If you are in a terminal, just use the man
command as in 'man program'. Often, you will see
a command written as whereis(1) - the number in
the brackets is the manual that the manual pages
for that command are in (if you don't type that
number, the man program will find the first
instance of that name (in the lowest numbered
manual) and provide you with that. So, you can
type 'man 1 whereis'
|and, in Konqueror...
Make your own maps
Maps are always nice to have on your website but they
are always owned by somebody. Strictly speaking, as far
as ownership goes, the map is a work of art and comes
under copyright. So, ideally, if you want the copyright
of a map, you need to make your own.
Usually, all you need on a website - or even on a piece of
business literature - is a fairly basic piece of artwork
that shows people the rough, topologically important
features so that they will have a fairly good idea of
where something is. They don't need something that looks
like an aerial photograph. So, let's make our own.
This is how I made one earlier and it shows the
positions and views of five photographs taken of the
recent (June 2007) high river levels in Derby (UK).
A good source of your area's topography is the
photographic images from Google Earth - effectively, this
is one of those so-called mash-ups that are so trendy to
have at the moment.
First of all, scale and orient the image to suit your
needs and then take a screenshot.
Next, open up your favourite, layer-friendly, image
editor - we are going to make good use of layers here.
|Paste your screenshot as a new image and
crop it slightly larger than you need - this is so that
you can edit it down later on - you can't edit it up.
create a transparent raster layer and call it 'Roads'.
Select the paintbrush, and draw the relevant roads onto
that layer, taking out any unnecessary details - in my
example, I had a layer of outline for the roads and
filled the roads in on another layer as well.
Next, you need to repeat the new-layer-draw cycle for
railways, rivers, key buildings, green areas and anything
else that you might need, using different colours.
Note that a tablet is good for this, by the way, and
adds more of an artistic feel to it.
Note that you should feel free to stylise the map you
are creating as much as you need to - remember that you
are not copying the image, you are interpreting it. This
is not just lawyer-speak either. At no point in any of
this process are you using any automatic tracing tool.
For example, if you were copying the image electronically
(getting a program to use the information stored in the
pixels to produce information in other layers without
user interaction), you might be using tools like the
magic outline mask tools; colour selection; and so on.
Here, you are doing it all by hand. The only input
that the bottom layer - the photograph - is having to the
process is that it provides you with a visual guide - it
might as well be in a different window as far as the
image processor is concerned because it is not
making use of it (If you were doing this on a system that
used the Beryl or Compiz window managers, you could put
Google Earth under your image and make your image
transparent - equivalent to tracing paper). Being in a
layer in the same image as your map does not contaminate
your map with other people's copyright unless you get the
image processor to draw your map for you. By keeping it
in a separate layer and making sure that it cannot affect
other layers directly when you flatten the image, you are
making sure that everything that is in the end map is all
your own work.
Next, create a white layer ('white ground' in the
image on the right) between the screenshot image and your
handiwork - this is going to be your background.
Also, add another one above everything you have drawn
('white'). This one is an easy way of toning down your
map - all you need to do is just change its opacity. The
reason for this is that the purpose of the map is to show
people where something is in relation to everything else
- a map that doesn't differentiate between various
features is of little use here. By toning down the map
(which is effectively the background), you are
emphasising the bit(s) that you want the user to be
Next, delete the screenshot layer so now, there cannot
be any of the original copyrighted photograph in your
image - it is all your own work.
|Now, add any text, your location (if
appropriate), using as many layers as you need above the
Here, I have added three layers:
- Text - so that each position can be identified.
If you were doing this as a map locating your
business, you would use your business name;
- Spots - marking the position so that it has a
definite place on the map. Again, if this was a
business, you would have a block in the shape of
your site or the location of the main gate or
whatever is appropriate; and,
- Views - here, I have indicated the direction,
field of view and roughly the distance of
interest covered by the shot.
These are on different layers so that I can change
their colours and opacity if I want to, or even tweak
their locations by a few pixels if I want. In the screen
detail, you can see how they locate (yellow lines) with
respect to each other.
|Now, make any final adjustments to opacity,
colours and so on, save a copy of the image in your image
processor's native format and then flatten the image.
your image does not contain any of the screenshot you
took - it is all your own, stylised interpretation. You
own the copyright.
Finally, crop the image and save it.
|This is the map in situ and, as you can see,
it makes it clearer where each of the photographs were
taken from and what they show.
PDF attached emails
You might have been getting a lot of emails recently,
that consist only of a PDF file attachment. Of course,
you shouldn't open them but just what are they? If it is
a virus, why aren't the virus filters filtering them out
and if it is spam, why aren't the spam filters filtering
there are plenty of unexpected file attachments that are
clicked on - around 100,000 or so every day that turn
people's Windows PCs into zombie servers - the most
recent trend is that spammers in pump and dump campaigns
are now using PDFs.
Normally, the text in a PDF is written using vectors
so that no matter how much you blow it up, you never see
pixels as little squares. However, these new PDFs use
dark-coloured, square blocks to form letters in the same
way that pixels do, and on the same sort of scale.
Blowing up these PDFs reveals them, as you can see. As
a result, there are no letters in the file and spam
filters fail to filter them out, just little blocks from
a specially prepared pixmap.
Even Optical Character Recognition has a difficult
task because the letters are all at different heights.
|Of course, there is no reason to have the
instructions to produce these little squares in some sort
of order, they can be shuffled so that even studying a
group of them won't reveal the letters that are supposed
to be formed. The only way to filter these out by looking
at the PDF is to render it and then try to analyse that -
a time-consuming and processor intensive activity (which,
no doubt, the spammer intends it to be).
So, we just
have to wait for the filter writers to come up with
something that works better than the current solutions.
Incidentally, while I have been writing the SuperDVD
content (about a week in early July), the spammers have
modified their program so that it now sends out
attachments that have no file name. One can only presume
that this is so that spam filters that look for a small
(a few tens of KiB) PDF attachment with some sort of
nonsensical name followed by .pdf will now have nothing
to go on and therefore they will get through (until the
filters are adjusted to quarantine emails that have a
no-name file attached - that narrows it down a bit).
Viewing log files in Windows
troublesome log files might end up as one line on some
text editors and, as it is supposed to be a log file,
this could represent a bit of a problem.
The output on the right shows the same log file
extract displayed using two Windows text file programs:
Notepad; and, WordPad.
Notepad is text-only so you would think that it would
be most appropriate to view a text-only file but you
would be wrong in this case. Notepad just looks at the
file as one large string.
When you drop a file into WordPad, it is able to
recognise where the end-of-line characters are and uses
them to create new lines for the following pieces of text
(although it does go on to make other new lines as well).
At least it makes some sense when you look at it which is
more than can be said for Notepad.
So, why does this happen?
|Most of the worlds web servers run on some
form of UNIX-like operating system. UNIX has a whole
different way of thinking about and solving problems. On
a UNIX-like system, such as Solaris, one of the BSDs or
Linux, the line ends have just a new line character
whereas NotePad expects a Carriage Return-Line Feed
(CRLF) pair - it hasn't seen them so it ignores the new
On the right are screen dumps from
Midnight Commander (MC). The top file is from the
original log extract and the bottom is the same file that
has been copied and then DOSified so that it will read
all right in Notepad.
You can see that the DOS version has an extra
character (0x0D) and expecting this is the reason why
Notepad won't read the UNIX file correctly.
|There are a number of solutions to this:
- one is to re-save it using Windows-style
- the other is to try loading it into a spreadsheet
such as OpenOffice.org Calc - this is
cross-platform so the same applies whether you
are running Windows on a PC or Solaris on a
To view this using OOo, open the file in Notepad,
press [Ctrl][A] to select all and then [Ctrl][C] to copy
it to the clipboard (you would do the same in Linux (KDE)
by using KWrite).
|In OOo, press [Ctrl][V] to start the paste
process then make sure the 'Space' checkbox is checked
and the text delimiter is double quotes.
You can see
how the field will be displayed at the bottom of the
With the log file formats, the only space that is
included within a field is the space between the GMT/UPC
time and the offset (here +0100 for BST). Otherwise, the
GET field, referrer, user agent and so on all parse
|With it looking the way you want it, click
on 'OK' and it will load a row per line, broken down into
cells for each field.
Drawing with a tablet
Tablets are coming down in price and people are
starting to ask that if they need one, is it really worth
spending a lot of money on one (I spied one in a camera
shop in Derby for over £200).
On the right, you can see the sort of thing that you
can buy from your local supermarket for just a little
above £20. This one is a Trust TB-2100 Wireless Tablet
and also has a wireless mouse if you want to use that as
The sensor size is roughly 4.5"x6" (just a
bit bigger than DIN A6 paper size) so a small print will
fit under it nicely, as you can see. It also has a
plastic sheet under which you can slide the photograph so
that the image is protected and held in place.
The pen has two programmable buttons and 2 extra
|The pen has a pressure sensitive tip that
sends effectively a grey-scale signal (it is actually 512
levels so that programs like The GIMP, PhotoShop,
PaintShop Pro and so on can use this extra information)
and this offers you a lot more than a simple on or off
pointer like the mouse.
Examples of the type of
modification that you can use this signal for include
brush colour, opacity, size and hardness.
Colour variation is usually taken as a value from the
currently selected gradient and in the image on the
right, you can see how size and colour are implemented in
Unless you are using a tablet for mapping large scale
images, you will probably find that a cheap one will do
everything you want it to.
Hashes in emails
Believe it or not, it is possible to verify that the
contents of a file has not changed, without having ever
seen it, had it in your possession or had access to it.
This can all be done by someone hashing their file and
sending you the hash in an email - you can always
telephone them to confirm the contents of the hash in
order to compensate for email's intrinsic security
weaknesses although the original file will not have been
So, supposing you get a hash in an email, how does
MD5 (Message Digest algorithm 5) is what is known as a
trapdoor algorithm. It works by taking a file that you
feed it and packing its length so that it is a multiple
of 512 bits long. It then takes it, 128 bits at a time,
minces it up and then processes that with the next 128
bits until the file is used up. By then, you are left
with a 128-bit value that can be represented as 32
It is called a trapdoor algorithm because there is no
way that you can derive the contents of the file from
which the MD5 function generated the hash. However, if
you receive an MD5 hash in email, you can confirm that if
a file generates the same hash, the file is extremely
likely to have the same contents as the original file.
make your own MD5 hashes from a file using the following
commands (using 'filename' as the hash source file):
md5sum -b filename
fciv -md5 filename
...for *BSD, Linux and Windows
respectively. (Note that you have to
download and install fciv from
http://support.microsoft.com/kb/841290/ for it to work
because this is not part of the default installation.)
You can see in the screenshot that the MD5 algorithm
is fast - less than 150ms for a 32MB file. The images in
'bigimage.bmp' and 'bigimage-1.bmp' differ only by 1
pixel which has is only 1 bit different - this giving
completely different hashes...
... and just to show that the file name does not
matter, images 'bigimage-1.bmp' and 'bigimage-1a.bmp' are
the same and so are their hashes.
MD5 produces a string of 128 bits but there are other
algorithms. SHA-1 produces a 160-bit string and together,
MD5 and SHA-1 provide the bulk of hashes although it is
said that SHA-2 should be the norm by 2010.
More efficient fans
You might have seen cowls attached to the air intakes
of air conditioning and cooling units on the flat
rooftops of various business units. However this not just
some fancy piece of hardware, it does have a serious
purpose - it's not to keep the rain off.
The cowls are critical to the efficiency of the fan.
If the fan is using all of the surface of its blades,
it will be able to provide a certain pressure drop for a
given flow rate. Reducing the extent to which your
hardware squanders the pressure drop and the use of the
fan's blades is what this is all about.
|Without the cowl, the air at the edge of the
housing has to travel around a sharp bend and the
resulting flow over the ends of the blades is turbulent
and a lot less efficient - the flow over the inner part
of the blades is laminar and works the way it should.
Turbulent air does not just mean loss of efficiency - the
turbulence also creates noise.
In addition to the fan
efficiency falling because only around 50 per cent of the
blade area is in effective use, there is also a higher
pressure drop over the intake.
|With a cowl - shaped like an elongated
inside of a doughnut - the horizontal vector for the air
flow at the edge of the intake is slower as the flow is
largely parallel to the direction of flow. This results
in the flow being laminar all of the way across the fan
blades, making the fan more efficient and producing less
In addition, scaled, fluid dynamic tests have
shown that the pressure loss across such an intake is
significantly lower therefore the unit as a whole
performs substantially better. Using water as a fluid and
various shapes of inlet, the coefficient for pressure
loss was around 20 times higher for a sharp-cornered
intake (as in the no-cowl example shown above-right) than
for one with a smooth intake such as the cowl.
As a matter of interested, you can make your air
intake consume an even higher proportion of the available
pressure drop by having the sharp-cornered design
protrude into the space from which air is being taken.
With a reduction in air velocity at the intake,
coupled with the virtual elimination of turbulence at the
fan, such an assembly is much quieter.
All you have to do is to get the manufacturers to make
Remember, you read it here first.
Dye sublimation printing
In the last few years, dye sublimation printing has
found its way into small printers at home and also into
photo kiosks in supermarkets where the quality of these
instant prints is reasonably good.
However, dye sublimation is not limited to printing
onto flat, specially prepared paper - it will also print
onto irregular surfaces.
Originally, this was done by taking a black and white
image and printing it out, laterally reversed, onto a
sheet of paper using a special photocopier with the
sublimation powder - a hot press transferring it to a tee
On the right, you can see one that I made in 1991 when
I was running a Modern Jazz group.
|The words were printed out on a Roland
plotter and other parts were pasted in (literally), such
as the East Midlands Arts logo and my line tone
caricature of me playing the double bass.
This was then
put through the special photocopier and the process
You can see that the definition was all right as well,
even though this has been washed literally over a hundred
In the heating process, the dye vaporises from the
heated paper and this gas then moves to a cooler surface
where it turns back into a solid. It doesn't melt at all,
it goes straight from solid to gas and back again.
You can see from the letter 'O' that the dye condenses
onto the top of the material.
This sweatshirt has lasted years of wear and if you
iron with a cool iron, the dye will outlive the shirt.
|In the last 16 years though, things have
improved and now, half-tones are possible, using any
Whilst these machines are well out of
the price range of the average PC Plus reader, you can
take an image on a flash card along to a shop and get it
printed onto a tee shirt.
You don't have to use images taken with a camera
either - you can make up any image (as long as it is
legal) and get it printed out.
|Colour definition is quite good - the
horizontal red line in the image on the right is just 2mm
wide making the colour mixing around 100 microns which
can effectively be ignored.
With your image, aim to get
around 150dpi (or thereabouts) with an image size in the
order of 12" (30cm) square. Also, remember that the
process is aimed at the family snapper so whilst they
claim to be able to take any image format, you are
limited mainly to JPEG although PNG is worth a try as
long as you have a JPEG image as a backup.
If you want to try to find out which image types you
can use, incorporate the file type in the name of the
file as well as the extension so you might have
'mypicpng.png' and 'mypicjpg.jpg' because, being a
Microsoft Machine, if you see the file name at all, you
probably won't see its extension.
Computers in films
Computers in films are usually given a visual task
that in reality is utter rubbish.
No system designer would send millions of images of
fingerprints over a network for a comparison similar to
those that we see in police and forensics dramas, for
example. In reality, the work is performed on the server
which, visually, is far less impressive.
This type of network faux pas, along with many others,
can be seen in many films.
However, there is one film that springs to mind that
does use a real program.
In Jurassic Park, in a scene where the 10 year-old
girl and a few others are trapped by a dinosaur trying to
get in, she goes over to a console and utters those
famous words; 'This is UNIX! I know this' and starts
playing with a 3D file browser.
|The browser in question is 'fsn' (File System
Navigator) and it ran on SGI IRIX which, if you look at
the border of the monitor, you will see.
|SGI has now switched over to Linux but
you can install the LGPL port, fsv (File System
Visualiser), which works pretty much the same.
screenshot, you can see the same type of visual output
seen in Jurassic park with files as blocks inside
directories, all linked together by a tree structure.
|To navigate, you can click on various
files or directories. To change the view:
- Zoom in and out by holding the mouse middle
button whilst moving the mouse up or down; and,
- Rotations are performed by holding [Ctrl] whilst
holding the left mouse button and moving the
When you click on a node (file or directory), it puts
it in the centre of the screen.
If you selected a directory, you can expand it by
right-clicking on it and selecting 'Expand' - this opens
it up and places it in the tree.
Right-clicking and selecting 'Properties' opens up a
dialogue box showing the file/directory's metadata.
FSV has another view, where everything is seen as a
progressively-subdivided, 3D block which you can
manipulate in the same ways as the tree view.
|As an alternative - one you are more
likely to find on a Linux system - you can use 'fsview'
which presents a progressively-subdivided, 2D block.
|In the same way as FSV, clicking on a
directory will select and expand that in the same way as
fsv and if you right-click on it, a menu drops down and
you can change its appearance and navigate.
World map in iris
is how to make an image of an eye - or at least the
iris part - that has a map of the world wrapped
around as the iris. I'm going to use the new Photoshop CS3 on Windows
and an old version of the The
GIMP (1.2.3) on Linux. Newer versions
have more capability but here we shall see how
flexible the software is. (Also, my son has
commandeered the server with The GIMP 2.2 on it)
all, you need to acquire a normal image of the earth. The
Mercator projection is fairly easy to find on the
Internet - you just need to find one without latitude and
longitude lines and with the land all of the same colour
(as an alternative, you can find one with the sea all of
the same colour - it is just so that you can select one
or the other).
This is a part of a map that I found (go into Google
Images and look for one there - you need one that is
maybe five times bigger than your final image because we
are going to mess around with it quite a bit.
One thing to bear in mind is that if you are editing
for the web (see the film-strip image above-left) then
you are only going to be aiming for 70-100dpi whereas, if
you are aiming for printed media, you should be aiming
for around 300dpi or more.
With this image, you can see that the Greenwich
Meridian is not included in the land areas above and
below it which makes it ideal (although if you have found
one with the water all one colour, that would have been
just as good).
However, this has been saved as a JPEG so where there
are boundaries - such as the coast line - you have the
normal JPEG artefacts.
With your image loaded, create two new layers so that
we can mess around with masks and colours without
destroying the original image before we need to.
map layer still having the focus (just click on it in the
layers dialogue box), click on 'Select',
'Color Range...' ('Select',
'By Colour...') and in the dialogue,
click on the land colour and, if necessary, adjust the
fuzziness so that you have all of your land.
Click on 'OK'
to finish. Now, select the top, empty layer.
Select a colour for the land (we'll use green here).
In Photoshop and The GIMP, just click on top-left box in
the foreground/background tool in the toolbox and the 'Color Picker' ('Colour Selection')
dialogue box will open. Select a hue by clicking on the
spectrum and select its saturation and value from the
large box. Click on 'OK'
('Close') to finish.
Next, we want to fill the top layer, inside the mask,
with our green.
- In Photoshop, select the flood-fill tool ('Paint Bucket Tool'),
make sure that 'contiguous'
is not checked and click on the image.
The GIMP, just click the mouse on the top-left
box in the foreground/background tool in the
toolbox and drag the colour onto the image. A
useful note is that this flood-fills the mask but
it doesn't change the identity of the current
Now, deselect the selected area [Ctrl][D]
Next, make a suitable blue - this should be darker
than the green.
Select the middle layer in the layers dialogue box.
Next, fill that layer with the blue in the same way as
you did the green.
Then flatten it by right-clicking on the image name in
the layers dialogue and selecting 'Fatten Image'.
Now, none of the original image remains. (if you were
really paranoid, you could delete the bottom layer before
you flattened the image.)
Next crop the image with the crop tool so that it only
contains the part of the map we are interested in (for
most of us, that goes from the southern tip of South
America up to the top of Russia. Now, we have a longer
and thinner map.
Next, we want to introduce the area that will become
our pupil. This black area needs to take up around 1/3rd
of the image. Make black your background colour by
clicking on the default colours (the little black and
white icon in the colours tool) and then click on the
reverse the colours icon to swap them over by clicking on
the double headed curved arrow.
Click on 'Image', 'Canvas Size...'.
click on the bottom-centre of the anchor box and adjust
the height so that it is around 25-50 per cent larger.
Then, click on 'OK'.
The map should now appear with black as a solid block
at the top.
In The GIMP,
type 1.5 into the ratio and drag the image block in the
window at the bottom, down to the bottom.
Click on 'OK' and the canvas size will be changed.
However, remember that it is the canvas size we have
changed and now, we need to right click on the layer in
the layers dialogue box and select 'Layer to Imagesize'.
You will now have the black area at the top.
If you are using Photoshop,
you need to make your image square (for some reason, it
will make your circular image elliptical if you don't).
Click on 'Image',
making sure that 'Constrain
Proportions' is not checked and
adjusting the width so that it is the same as the height.
Click on 'OK'
and your image should be square.
click on 'Filter',
and then click on the '-' button a few times so that you
can see some of your image.
and then 'OK'.
Unfortunately, if you want to rotate your image so
that something other than the middle of it appears at the
bottom, you will have to do this later on (rotate it
through an arbitrary angle).
In The GIMP,
you don't need to make it square to start with.
Click on 'Filters',
Here, you can change the offset angle so that if you
want the Americas at the bottom, you can. Select, 'Map Backwards'
and 'Map from Top',
changing the angle to around 85 or so, depending upon
which bit you want at the top.
|If you chose to have the iris at the bottom
and have Australia/New Zealand at the top, deselect, 'Map
Backwards' and 'Map from Top', changing the angle so that
your country of choice is at the top - Australia is
around 300 degrees.
Note that this will vary according
to the Mercator projection map you started with.
Now, you need to add an alpha channel (transparency)
to your layer. We did start off with a JPEG image - these
don't support transparency - so we need to get our image
into a transparent layer. There are a number of different
ways of doing this.
use the circular mask ('Elliptical
Marquee Tool') to cover the image - this
will give us our highlighted circle. Now, we can copy the
image and paste it back into the same image which will
automatically end up as a new layer, with transparency.
Now all we need to do is to right-click on the 'Background' layer
in the layers dialogue box, then click on 'Delete Layer' and
confirm in the dialogue box that pops up.
In The GIMP,
right-click on the layer in the Layers dialogue box and
select 'Add Alpha Channel'. Now, select the fuzzy
selection tool (the magic wand) and select the two white
areas to the side of the iris. Press [Ctrl][X] to cut
them out. To get to the same physical state that we are
in with Photoshop, just use the crop tool to highlight
the entire image, click on 'Auto
Shrink' and click on 'Crop'.
Your image should now look something like the one on
All we need to do now is start to make it look like an
In order to do this, we can keep on adding layers that
modify the image below until we get something that looks
just the way that we want it to. First of all, we might
want to adjust the blue and the green to get them roughly
how you want them (brightness, saturation) although you
don't need to because you can always do that later - it
just makes the next steps easier.
So, what layers do we need to add?
This is the image that we are starting with.
I've desaturated the colours and moved them
closer to each other.
Use the magic wand selection tool to select
the whole, non-transparent part of the image
(turn the threshold/tolerance up to 255 to select
it) and then turn it back down again and deselect
the pupil (on Photoshop, hold down [Alt], on
The GIMP, hold down [Ctrl].
Now, we can draw what we like and it will only
affect the iris.
Create a grey layer and in the layers
dialogue, select multiply and an opacity of
around 50 per cent - you can mess around with the
function of the layer and the amount of that
effect later on.
Then use the dodge and burn tool or white and
black paint to make a pattern that is like the
radial structures on the iris. Using a tablet
makes this easy as you can change the size and
intensity of the strokes as you make them.
Now that we have the fine structure on the
iris, we can add to the overall shape. The outer
edges have their illumination reduced by the edge
of the structure and the inner edge curves
You can make this by using a large, soft brush
and paint with black around the edges.
Now, we highlight the lower part where light
coming in from above will be bent inwards and
illuminate the iris. We also draw in a bit of a
shadow where the light coming in from above will
be aimed elsewhere.
This layer is added as an overlay layer. You
might want to adjust the proportion of the layer
we added at step 14.
First of all, get rid of the mask you have
been using. Next, create a new layer and then
make a mask that is the shape of the light you
want to be reflected in the outside of your
cornea - remember that it should be smaller than
it is going to end up.
Now, choose white as the current foreground
colour and then select the gradient fill tool.
Select foreground to transparent and then drag
the mouse down over the highlighted part of the
Remove the mask.
Now, you need to distort the image so a
lens-type distort will do a good job.
click on 'Filter',
[sic] and make sure that it is on '100%'.
Click on 'OK'
to make the Distortion. If the effect is not
enough, press [Ctrl][F]
to apply the distortion a second time.
On The GIMP,
click on 'Filters',
Check the 'Make
checkbox, change the 'Refractive
Index' to 2.00 (it is a heavily
curved surface) and click on 'OK'. If
the results aren't quite to your liking, you can
change the refractive index and so on.
We now need a reflection off the back of the
lens. Duplicate the layer we have just made.
this can be done by right-clicking on the layer
in the layers dialogue box and then selecting 'Duplicate Layer...'
and clicking on 'OK'.
In The GIMP,
you can either:
- right-click on the layer in the layers
dialogue box and then select 'Duplicate Layer;
- you can drag the layer from the layers
dialogue box and drop it on the image
Now, we have the same image.
click on 'Edit',
'Transform', 'Rotate 180degrees'
and then drag your layer back to where you want
it. Now, click on 'Edit',
and whilst holding down [Shift],
drag the corner of the box until it is small
enough to fit in the pupil. Then, double-click in
the box. Next, drag the image until it is in the
right place and adjust its opacity until it is
barely visible (around 10 per cent).
In The GIMP,
Next, click on the 'Scaling'
tool and then on the image. Now, drag the image
until it is small enough to fit in the pupil.
Then, click on 'Scale'.
Next, drag the image until it is in the right
place and adjust its opacity until it is barely
visible (around 10 per cent).
|Now, we have an iris
and pupil, complete with reflections that we can
add to an eyeball and eyelids.
Multiple Document Interface (MDI) in
document interfaces (MDIs) have been around for many
years - on the PC, they existed in the early 1990s using
a 80x50 character DOS interface where they were extremely
quick on a processor running at even 16MHz.
On DOS or any GUI, the MDI kept everything in one
window and made it easy to control that program's child
windows. However, things have changed since then.
Now, we have larger displays and run a number of
programs at the same time so, whilst we are editing one
image, we could be looking at some instructions or other
notes - the nature of the MDI is to take up a whole load
of your screen so that you cannot use it for anything
Image editors like The GIMP have got around this by
using multiple windows so that you can move them around
from place to place, mingling with other programs or even
sitting on a number of different desktops - something
that you don't see on Windows or Mac OS X which are both
So, how do we change this?
In PhotoShop, make sure that you can see some of your
desktop and then, grab hold of an image and drag it out
of the MDI. At first, it will slip under the border but
keep going and once you've dragged it past the border, it
will appear outside the MDI.
For the control windows such as 'Layers', 'Color', the
tool box and so on, grab hold of the lighter-coloured
area, just inside their borders and drag them - they
break away just the same and soon, you can configure it
the way you want - complete with other programs
positioned so as to make your workspace more functional.
PhotoShop won't let you get away with doing this to
all of its windows but once it is the way you like it,
click on 'Workspace', 'Save Workspace...' give it a name
and click on 'Save'. Next time you open PhotoShop, your
windows will either be there or you can click on
'Workspace' and select. The only disadvantage is that
when you open a new image, you have to drag it out of the
MDI and zoom in - a small price to pay.
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