Post image for A love letter to Demosaicing Algorithms, Digital Photography and miPhone

A love letter to Demosaicing Algorithms, Digital Photography and miPhone

by Melanie Gow

I feel in love with it believing that love dies and passion fades, and in that moment I became the kind of romantic only a cynic is truly capable of being. I owe this to The Bodyguard. Yes the movie, the one with Whitney Houston and Kevin Costner, yes.

I was invited to see the first six minutes of digital footage in a major movie, at an Apple technology symposium – in 1990.

I was using 35mm film in my camera of course, and had chosen the dry splice and sticky tape route for editing the feature film I was about to make, Intimate with a Stranger  – I wanted to go Avid, but it was too new. It was American and only publicly traded the year I started filming at Shepperton Studios, it was too much of a culture change, I couldn’t find an editor happy to use it.

It was too soon for the revolution. Nobody would get into a conversation about it anywhere on Wardour Street.

When I saw the those six minutes and someone expanded it on a computer screen so I could see the pixels, it was like seeing a chest cracked open and watching the heart beat under your hand. I fell in love. In those six minutes I knew I had met ‘the one’, I have spent over two decades searching for a way to be together.

Digital is an extraordinary playground with three primary colours, two numbers and an electronic system.

Conventional cameras depend entirely on chemical and mechanical processes – you don’t even need electricity to operate them.

It is stating the obvious but, digital cameras, of all variations, have a built in computer – all of them record images electronically.

Essentially, a digital image is just a long string of numbers, 1s and 0s, that represent all the tiny colored dots, or pixels, that collectively make up the image.

All filtered through the three primary colours.

The first consumer-oriented digital cameras were sold by Kodak and Apple in 1994.

Digital photography is still ‘old school’ in that it is about painting with light. There are still a series of lenses that focus light to create an image of a scene. But instead of focusing this light onto a piece of film, a digital camera focuses it onto a semiconductor that records light electronically.

The process is entirely about light or absence of it across the grayscale. Each photosite can only track the total intensity of the light that hits its surface.

Each pixel carries intensity information, only.

We are talking about light here, and that is all. This process is about light being reflected or absorbed, and it is a black and white process.

I am sure we all know from physics class at school that the colour of an object is not contained in the object, colour is the result of the light that strikes a surface and which waves are reflected.

A digital process has to use something to record and interpret that information. Digital cameras use filters to bring the colour out. There are several ways of recording the three primary colors in a digital camera. The highest quality cameras use three separate sensors, each with a different filter with split beams, but the majority of small cameras use a demosaicing algorithm. Fitting a colour filter array over each individual photosite.

In case you don’t know what this looks like, it’s a primary coloured checkerboard, red and green squares in rows alternating with blue and green rows across a square. By the way, there are more green squares because we, as a species, are not equally sensitive to all three colours

By breaking up the sensor into a variety of red, blue and green pixels, it is possible to make a guesstimate of the true colour. Some of the more advanced cameras subtract values using the typesetting colours cyan, yellow, green and magenta instead of blending red, green and blue.

But, all that aside, that is what you are playing with when you are working with a digital image – when you “edit” you are playing with the intensity of colourless light reflected, pixel by pixel, and the effect the combinations of red, blue and green filters have on it.

You are tampering with that information held electronically, when you edit.

And the sensitivity of the human eye to those colours.

And nothing more. But, nothing less.

That allows me to tell a story, for me imagery is about The Story. It was as a film maker it is as a photographer. What moment am I catching, what is happening in it, what am I seeing and how does it make me feel.

Observation, perception and interpretation, it’s probably largely solipsistic as it is about my exteroceptive relationship with the world and not intended as an objective report on it. Although I do use images to report on what I see, to tell others about things that inspire me, but I always want to reach past what the eyes see to a feeling.

Digital photography has, and does, give me the means to quickly capture moments I see, and then play with them to convey the feeling I have.

Mobile photography goes one step further and allows me to do this unobtrusively, almost as I see it without a camera between me and the world.

PS Ironically you couldn’t see those six digital minutes of film at the time because there was no way to deliver a digital film into a cinema. The Last Broadcast made cinematic history on 1998, when it became the first feature to be theatrically released digitally, I missed it as Cannes Film Festival as I had this whole other project on my hands producing boys.

However, a happy result of becoming a parent was that I owned one of the first digital copies of Toy Story, the first computer generated movie and delivered on digital. I was delirious. When I saw it I had to ring someone I was so excited, “but you can see the texture on his ears.”

But all I could do was watch and marvel, digital was out of my reach once again as I was out of step in time. Now that my mobile phone can combine my love of photography with a digital camera and the ‘apps’ to edit it all, I feel like creativity is in the palm of my hands. Finally the timing is perfect, my true love and I are in the same place at the same time and are meant to be together..

I can wander the world and convey what I see and how it feels. It makes me feel articulate. If words were enough I wouldn’t take pictures.

In the mantra of the Bodyguard; I never let it out of my sight, I never let my guard down, I never fell in love.

Melanie Gow is currently working with her iPhone on “Merry Lives of Windsor”, a black and white episodic encounter with people who live in Windsor, UK, over a year.

Melanie Gow is editor at Glow Magazine, an online journalist, mobile photographer and iArtist, producer and cultural events organiser.
She is on Instagram as @Princesss_MeLeia and on Twitter: @melgow

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