Digital Images



1. Intro


We already made the point that we can hardly imagine a world without computers. Well, computers aren't analogue, they are digital. They basically are a combination of millions of on/off switches, two states (0 or 1, open or closed, true or false, black or white...). No grey areas here.


We also said that computers could find their place in helping us in our creative endeavours. Music for sure, and of course, the subject of these notes: digital imaging.


If you take pictures you probably use a digital camera. You may also use a scanner, knowingly or unknowingly (any copying or sending a fax starts whatever it does by scanning documents). All of which involves lightsources, sensors and memory.


The digital images world obviously gives us a lot of opportunities for indulging in all the creativity we can come up with. All this mostly at low cost. Possibilities we could not imagine 10 years or even 5 years ago. Apart from this role in the creative world, digital imaging and image analysis also finds a lot of applications in the business world, and especially in manufacturing. Image analysis can help with time studies, as the second example on page 3 of our 'MANUFACTURING' section shows. It is often used to automatically detect quality problems and even automatically sort out defective elements. It can be used combined with other technology to show temperature distributions.


In the next few pages we will give some hints about digital images.


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2. The Myth of Resolution


When you see any advertizing for digital still cameras, you can't help noticing how all the products seem to bid up against each other in the 'higher is better' resolution case. It is however important to understand that not everything revolves around the number of pixels offered up by the resolution.


First of all, it needs to be clearly understood that the sensor is the equivalent of the chemical film in the old systems. On the old systems on any given system the sharpness of the picture, which is the same as resolution, was determined by the so-called grain of the film. This itself was determined by the chemical particles. More sensitive film usually showed more grain. On the old systems for a given film the sharpness was determined by the quality of the optical system. The logical conclusion of all this is that by replacing film with an electronic sensor the same rules keep applying: a given sensor will give sharper pictures with a better optical system. Not only that, but even the analogy regarding the sensitivity stays mostly true. Higher ISO settings mean more amplification of the signals and hence more production of noise. The advantage of the digital world of course is, that you are not limited by the ISO grade of your film, but that you can in the middle of a photosession just change the ISO setting of your camera.


A second point that needs emphasis is that you can waste part of the resolution the camera offers. The fact that it has become so easy to manipulate our digital pictures after taking them, often makes people a bit careless about the actual taking of pictures: sharpness, composition and lighting can so easily be adjusted in free and cheap software on a PC or even at a photo kiosk in the shop. So don't count on sharpening afterwards, but focus properly. Too much sharpening afterwards easily results in an unnatural look because of unwanted artifacts introduced by the software. Be aware of how the autofocus works, so that you avoid that the camera focuses on the wrong place in the picture. Don't count on the adjustments in brightness and contrast software makes possible. First of all, what is burnt out, doesn't contain hidden information you can bring back. Also what is too dark you may be able to lighten, but you may very well introduce a lot of noise that way. And unless you use the more complicated aspects of better software to isolate dark or light spots, whatever adjustments you make, work on the whole picture. This means when you lighten the dark parts, you burn out the light parts at the same time. The same way darkening the burnt spots will turn darker parts to black.


Which brings us to composition. Whenever you crop a picture in software, you are throwing out part of the picture, which is the same as keeping a part which contains less pixels or points than the original picture. Of course when you print the cropped image at the same size as the original image the print will be less sharp, because it represents less separate pixels. Hence the need to compose your picture as accurately as possible so that you need to throw out little or nothing. It is of course also true that the more resolution a camera gives you, the less important this becomes. But it is not at the point yet that it has become irrelevant. Maybe with 50 MP cameras, which by the way do already exist, but not at prices any but the most well paid professional can afford.


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3. Some hints regarding software


There is a lot of software out there which allows you to manipulate digital still images. Some is proprietary software that comes at a cost, but can be very powerful and what you need to compete yourself with your work in a commercial environment. Some is free software for use on proprietary operating systems and some is free for use on free and open source software platforms.


Amongst the proprietary software packages you can't go wrong with anything from Adobe. Its Photoshop software is considered the de facto industry standard. And because Adobe offers a lot of other packages, and even combines them in a software suite, it can make it a lot easier to incorporate your work in other applications such as desktop publishing, documents (PDF) and web pages.


One important distinction between the simpler software and the more powerful software is the ability of the latter to work with layers. Think of your pictures as transparent so that you can combine several on a lightbox with varying levels of transparency and I am sure you see how this is a powerful tool. For one thing, if you go back to our comments about darkening or lightening pictures in the previous page of this 'DIGITAL' section, you can see how you could combine layers in which the darker parts are lightened with a layer in which the lighter sections are darkened. Although this still would require a lot of work isolating these parts, the more sophisticated packages usually provide more and better tools for selection. Also bear in mind that the brightness/contrast adjustment is the simplest of lighting adjustments. Packages which allow gamma correction give you more control.


And then there is the issue of which file format to use, starting with your camera. If there is a RAW setting, we prefer to use it for real quality work. It provides raw information coming from the sensor with little or no processing in the camera, which also implies no assumptions are made for you by built in software in the camera. It used to be so that not all editing software could deal with the RAW format, but now they mostly can. Even on Linux there is some very good software out there that deals specifically with the raw format: look up 'RawTherapee' and 'UFRaw'.


For relatively simple work, such as cropping and some sharpening you may want to have a look at Irfanview which is available free for MS Windows. For some more editing power, often mentioned as alternative to Adobe Photoshop, but free, the GIMP is a nice possibility with loads of effects, expandability through programming and of course layers. It may not be the most intuitive interface, although it is getting better. It is also catching up with other software when it comes to particular standard colour formats. And it is available free for Windows and Linux.


And if you want to take it to the next stage and do some real digital creation in 3D, and maybe even throw in some animation, there is Blender. Again maybe not the most intuitive interface, but extremely powerful and coming originally from a commercial product but now free and available for both Microsoft Windows and Linux environments. Maya and Xara are commercial products available for Windows, with Maya also in 64 bit version for some Linux distributions. There is also a xaralx version available in the distribution repositories of Ubuntu Linux.


Whether you go all out and spend lots of money, or keep it simple and cheap, the means are there to let your creativity run wild. Results are not guaranteed to be proportional to the money spent.


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4. Some hints regarding pictures


When talking to photographers, be they professional or amateur, you will probably get a lot of advise. What you should bear in mind though is that a lot of it can be highly subjective. Anyhow you should never let these 'rule of thumb' aspects get in the way of your raw creativity. On the other hand your creativity can also feed on the insights and ideas of others.


One of the ways we sometimes try to think about pictures is along the line of themes. We once made a photo essay, which we will share here with you, illustrating a number of themes, such as:


churches, cityscapes, details, lines, extreme, fauna, flora, framed, landscapes, people, rambling and hiking, reflection, glass structures, that time of day, that time of year, waterfront.


Most of these theme titles speak for themselves.


'Extreme' are pictures which were modified in rather extreme ways through software.


'Lines' often give some extra depth to a picture, especially if they are neither vertical nor horizontal. 'Framed' means that there are elements around the edges of the picture which are closer by: it also creates depth.


'Rambling and Hiking' belongs to the family of 'telling a story' pictures (rambling is British for the North American hiking).


'Reflection' speaks for itself, but the title picture is a bit tongue in cheek, showing that other type of reflection.


'Glass' within structures often does the same as 'Framed'.


'That Time of Day' shows the effects of different light conditions.


'That Time of Year' does the same and adds some seasonal elements.


'Waterfront' also speaks for itself. Themes can of course cross each other, with waterfront and reflection as well as framed and glass being the obvious examples.


Add to that the occasional mystery and wit in our choice of titles and we are ready to entertain.


Enjoy!

DIGITALLY YOURS

Digitally Yours

CHURCHES

Church

CHURCHES

Tabernacle

CITYSCAPES

From Mont Real

CITYSCAPES

CN Perspective

CITYSCAPES

Corning Sidewalk

CITYSCAPES

Stadsbibliotheek

CITYSCAPES

Jazz the Morning After

CITYSCAPES

Le Metro

CITYSCAPES

Marche du Bon Secours

CITYSCAPES

Musee Carnavalet

CITYSCAPES

Sailing

CITYSCAPES

Skyline

CITYSCAPES

Tower Bridge

DETAILS

It is in the Details

DETAILS

Steam

EXTREME

Extremely Different

EXTREME

Blue Moon

EXTREME

Le Vieux Port

EXTREME

Blue Wires

EXTREME

The Birds...

EXTREME

...and the Bees

FAUNA

Wink at Me

FAUNA

Bad Hair Day

FAUNA

Bison

FAUNA

British Beavers Eh

FAUNA

Dragonfly

FAUNA

Morning Sheep

FAUNA

Misty Sheep

FAUNA

Strictly Carnivorous

FAUNA

Strolling

FAUNA

Where is the Sand

FLORA

Flowers

FLORA

Stirling Pink

FLORA

Tulips

FLORA

White

FRAMED

Electric Frame

FRAMED

Carmen

FRAMED

Entrance

FRAMED

Framed

FRAMED

Maids of the Mist

FRAMED

Courtyard

FRAMED

Parliament Hill

FRAMED

Pond

FRAMED

Shipyard

FRAMED

The Ferry

FRAMED

The Islands

FRAMED

University Avenue

LANDSCAPES

South Downs

LANDSCAPES

After the Harvest

LANDSCAPES

Angel

LANDSCAPES

Black Nevada

LANDSCAPES

Cornish Hay by the Sea

LANDSCAPES

Cup and Saucer

LANDSCAPES

Going Down

LANDSCAPES

PEI Potatoes and Lobster

LINES

Double Parked

LINES

Bridge Lines

LINES

Caceres

LINES

Conservation Boardwalk

LINES

Flanders Fields

LINES

Green and White Perspective

LINES

Las Casas Colgadas

LINES

PEI Marsh Boardwalk

PEOPLE

Cherry Pink and Apple Blossom Blue

PEOPLE

After the Concert

PEOPLE

Bored

PEOPLE

Mule Ride

PEOPLE

Petanque

PEOPLE

Pompidou

PEOPLE

Soledad

PEOPLE

Winter Smile

RAMBLERS

Ramble On!

RAMBLERS

Canola

RAMBLERS

Leading the Way

RAMBLERS

Stile

RAMBLERS

Walking the Distance

RAMBLERS

Wheat

REFLECTION

Forgotten Something

REFLECTION

Camera

REFLECTION

El Quijote

REFLECTION

Flags and Tower

REFLECTION

Harbour Reflections

REFLECTION

On a Wing and a Prayer

REFLECTION

Science

REFLECTION

Squares

REFLECTION

St Johns Flags

REFLECTION

Striped Tower

REFLECTION

Winter Tree

GLASS

Glass Canope

GLASS

Glass Floor

GLASS

Inviting

GLASS

Lighthouse Window

GLASS

Palace

GLASS

Rafters

GLASS

Visitor Centre

STORMY WEATHER

Overflow

STORMY WEATHER

On a Riverboat after the Storm

STORMY WEATHER

Shower

STRUCTURES

Red Mill

STRUCTURES

Cloister Garden

STRUCTURES

Roman Perspective

STRUCTURES

Stone Lace

STRUCTURES

The Red Castle

STRUCTURES

The Sportsman Inn

STRUCTURES

Who wants more?

THAT TIME OF DAY

Hanging Out

THAT TIME OF DAY

Dead Tree

THAT TIME OF DAY

Gull Lake I

THAT TIME OF DAY

Gull Lake II

THAT TIME OF DAY

Late Lobster

THAT TIME OF DAY

North Sea

THAT TIME OF DAY

On the Waterfront

THAT TIME OF DAY

Serpentine Night

THAT TIME OF DAY

Sunset Harbour

THAT TIME OF YEAR

Seasonal

THAT TIME OF YEAR

White Niagara

THAT TIME OF YEAR

Red

THAT TIME OF YEAR

Yellow and Red

WATERFRONT

Walking on Water

WATERFRONT

Above the Waterline

WATERFRONT

Beachy Head

WATERFRONT

Bobbing

WATERFRONT

Bruce

WATERFRONT

Cross Hatch

WATERFRONT

Fishing

WATERFRONT

Gull Fries I

WATERFRONT

Gull Fries II

WATERFRONT

Misty Waters

WATERFRONT

Red Sands

WATERFRONT

RX58

WATERFRONT

Shortbread

WATERFRONT

Twixie

THE END

The End


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