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| Restoring Pictures Digitally |
Traditionally photographic
restoration has required photographing the original to re-balance
the colour / contrast and then using a fine brush to restore scars
on the image. 
I admit this is a brief description because the point of this page
is to describe some of the techniques you can use on a computer to
restore photographs.
First thing to bear in mind here is that the final product is a new
image based on the original so that if it all goes completely wrong
you can do it all again.
Step 1. Scan the original:
This will normally be done with a flatbed scanner, you can read all
about the latest and greatest available ones in reviews on the
internet or in a magazine. I have had good results from moderately
priced units. My current one is a HP 4200C which is about 2 years
old now but still churning out the goods.
 Scanner
information should give you 2 resolution figures, one will be the
optical resolution of the scanner, the other will be a much higher
resolution. The higher resolution is done mathematically based on
the optical resolution, the optical resolution is a measure of what
the scanner can actually "see". In general the driver
software is no better (and sometimes a lot worse) than digital
imaging programs at creating the higher resolution images.
Generally you should only scan up to the optical resolution of the
scanner. You won't get any more "real" detail out of the
image than that. Photographs vary quite a bit in how blurred they
are anyway. You need to experiment.
Step 2: Edit the picture:
 For
this you need a program like Paint Shop Pro or Adobe Photoshop,
there are lots of others and prices vary. From the things I describe
here you can create a list of features to look for. I use an old
version of Adobe Photoshop for some things and Paing Shop Pro for
others. I have other programs but I always end up coming back to
these two. It's a case of what you get used to.
There are several things that you can do to pictures without
changing the underlying image. Before you do anything else follow
the golden rule SAVE YOUR WORK OFTEN. I know programs have undo
features but you never know when the computer is going to hang up
and loose your work. So save your work on a project in a series of
files, number them or something like that so that you can always go
back when you find you've made a mess.
Brightness and Contrast are good things to start playing with.
Brightness speaks for itself. When you increase the contrast you
actually reduce the number of colours in the picture, In a black an
white picture try increasing the contrast all the way and you will
see that you have only 2 colours, black and white. As you reduce
contrast more in between shades come available. Usually increasing
brightness will mean that you need to increase contrast too to stop
the colours becoming too washed out.
Colour balance, colour to black and white translation are other
things to play with. Sharpen is a function that works well with
small images but doesn't have much effect on large images. In
printed output sharpen has some side effects too.
Again you should experiment, there is never a single answer with an
image.
My choice for black and white images is to scan in colour, save it.
Convert to black and white in the image editing software, save it.
Adjust brightness and contrast, Save it. Check if there are any
other improvements.
You can see here that adjusting brightness and contrast has
actually removed some scratches at the top.
If you have an older PC like mine then some of the transformations
take a while to perform.
Step 3: Repair damaged areas:
One straight forward method is to crop the picture to remove bits
around the edge.
As you can see here cropping makes a good start to repair, the size
of the triangular gash was reduced a lot.
 Repairing
scars in the image can be a bit daunting but there is one tool that
is essential to get the hang of and that's the clone brush. This
allows you to copy a texture from one area of a picture to another.
This way you can repair damaged sections with ones that look
similar. You will have to adjust the size of the brush that you work
with depending on the job you are tackling. Also you can zoom in to
an area to work at very high resolutions easliy. Remember to save
work frequently. Also when working zoomed in you should remember to
zoom out after completing sections of work just to make sure that it
still looks OK. This picture has a major fault (from my point of
view). I was rushing to get it done, I was working zoomed in and not
zooming out and was not saving frequently. We learn best from
mistakes.
Thi s
picture was in quite a state. It had been folded, torn, repaired
with tape (on the back). The image was converted to black and white,
colour balanced and generally messed around. The reconstruction work
was extensive.The big triangular tear on the right where the red
tape shows through on the scan was replaced by some wall that was
copied with the clone brush. The hardest part was reconstructing the
eyes that were lost in a torn part. This was done initially by
working gradually from the edges of the tear towards the middle and
then copying eye features with the clone brush and also some
straight painting.
The results are not perfect but once printed it is so much better
than the original. You tend to reach a point of diminishing returns,
where you can continue making more and more changes but not making
the final product significantly better. The work here took about 6
hours and it was quite intensive.
Step 4 Printing:
Printing is a work of art in itself. Most printers that will do 720
dots per inch or better will do a good job. The thing to look out
for is the printer driver. You can spend hours getting everything
just right on your screen, print it out and have a completely
different picture on your paper.
Professional equipment is expensive for a reason, it is all
calibrated to a known set of colour scales, that means they print
what they see. We usually don't have that luxury.
One things to check out is whether the image looks the same on
someone elses monitor. Some image editing software like Photoshop
include monitor calibration charts. You can adjust brightness and
contrast on your monitor.
Another pitfall is printer drivers, they quite often do colour
balancing of their own on images sent to the printer. This sometimes
results in some odd colours appearing. Check out the printer driver
settings, there is usually scope for limiting what it does for you.
You may find it does a good job for you, in which case go with it.
Summary
There are magazines and places on the web that give advice on image
manipulation, these can be useful but you just can't beat having a
go. Make a few notes of what works and what doesn't, what has good
effects and what you can miss out so that you can look it up and
save time next time.
The main thing is to enjoy it.
By the way, the fault in the picture is with the tallest girl's
sholder where it meets the sleeve. The one on our right is "puffed
up", when zoomed in this looked like dirt on the picture and
the one on our left got erased, it doesn't show too much on these
small images but it is obvious on the printable one, oops. I'm the
only one to notice it usually. |
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