Getting the Message Across, Images

Getting the Message Across, Images


Hi,
I’m Stéphane Faroult, and this is the fourth installment in my video overview of my book
“Getting the Message Across”, how to use presentation software such as PowerPoint to
give interesting technical presentations. Chapter four is entitled “Editing Images”
and illustrates how you can use images in your presentations, as well as how to modify
them with the free program Gimp to make them suitable for a presentation. In the book I illustrate it with pictures
of the first working mechanical calculator, first built in 1642. In this video I’ll show you a number of
options using pictures of a later calculator that I took in one of the really great museums
in the world, the Kunsthistorisches Museum in Vienna, Austria, and more specifically
in a subsection called the Kunstkammer. One of the exhibits is a 1727 calculator built
by a clockmaker called Anton Braun. This calculator is dedicated to the then Habsburg
Emperor, Charles VI, and according to the explanatory label was primarily used for land
surveying calculations. I took two pictures with a smartphone, and
they aren’t high quality pictures. The calculator was in a glass showcase, which
means reflections. The second picture is blurred, but that’s
usually something you only discover when you are back home. So, in a kind of history of computing devices,
how could I present my only acceptable picture? I have seen many people present something
like this. This is a very dull way to present a picture. The borders are distracting. Remember that we are automatically attracted
by contrast, and we are adding here contrast that takes attention away from what we are
presenting. There are two solutions. The first one, if the resolution is high enough,
is to make the picture cover the whole slide surface, from edge to edge. It will probably require moving the text around
and changing its color for better legibility. The second option is to remove the background. Some versions of PowerPoint have a built-in
tool for that, but it works better on logos and images with a very strong contrast between
foreground and background; with most photographs, it’s better done with an editing program
such as Gimp and I explain how to do it in the book. We can even remove the original shadow, and
replace it with a shadow added by PowerPoint. A picture without a background can be more
easily scaled, if you want for instance to present several antique mechanical calculators
on the same slide. We have however one problem, which happens
frequently, with this particular picture: I didn’t frame it carefully enough, and
I cut one of the feet. It was hardly noticeable when the image was
edge to edge, because this straight line was matching the bottom edge of the slide. It’s far more visible when I no longer align
the picture with the edges. One option is to soften the bottom part of
the picture, which is a technique I also explain in the book, and it can be done in a matter
of seconds. It works so so in that case, but I use it
frequently with portraits. I couldn’t find a portrait of Anton Braun,
but this is emperor Charles VI, whose name is engraved on the calculator. We have the same problem as before of a dull
rectangle with strong contrasting lines. We can improve it by removing angles, which
softens the image. Or we can remove the background, which leaves
visually shocking straight lines, and soften the bottom part so as to turn it into a kind
of vignette. This enables us to give to the portrait the
size we want, and to place it wherever we want, even across the edge of the slide. Now, there is another option for the missing
part of the calculator foot: copying bits from the feet we see fully, and recreating
the missing part. That’s also something you can do relatively
easily with Gimp by copying, pasting, flipping, and using a few tools for smoothing the image. Now what about the other picture, the blurred
one? Can’t we use it in a way or another? I have always seen the advice “only use
high quality pictures” but this is easier said than done; in a few cases, the only image
free of rights that I could find was either of low quality or at a low resolution, and
when you were scaling it up it was becoming very pixelated. The truth is that there are cases when the
real choice is between a mediocre picture and no picture at all. Programs such as Gimp (and some versions of
PowerPoint) include tools called “filters” that modify an image. Such a filter is the sharpening filter, which
may improve a slightly blurred picture such as this one; however, it won’t help on a
pixelated picture and there is another Gimp filter that I like very much, which is called
“oilify”. This filter blurs neighboring colored pixels
and gives an appearance of oil painting. It won’t make the image any more precise,
but it dishonestly suggests that the lack of detail is an aesthetic choice rather than
a technical constraint. It may save a poor picture. The other option is to keep the image small
enough so that it still looks OK, even when projected on a large screen. However, instead of keeping it as a dull rectangle,
use the image formatting options to add a white margin suggesting a paper photograph,
and tilt it slightly so as to suggest a photograph that was casually dropped there. This is something that works very well when
you have several pictures, none of which is very good, and it requires very little work. These are some options that may help make
your presentation more attractive from a visual standpoint, and keep the interest of your
audience.

Dereck Turner

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