The digital steam video
He pointed up at the huge billboard above their heads and smiled triumphantly
“This is the new invention I wanted to show you”
She looked quizzically at the picture on show, not understanding his enthusiasm considering it showed merely an advertisement for washing powder. Surely he had not developed some new kind of soap. Suddenly a hand appeared in the picture and took hold of the packet and began a small scene of action.
“Oh,” she exclaimed “Moving pictures, but without a projector as far as I can tell.”
“Yes it is a new method of producing animated advertising.” He replied “The whole image is made up of thousands of tiny little beads; six sided with a different colour on each face. By rotating each bead in turn to the correct colour to match the image being displayed, we can make up this coloured picture. It looks solid from this distance but if we were to get up close you would see each image is made up of lots of tiny dots, like a pointillist painting.”
“Marvellous but what makes it move?”
“There is a little shuttle behind each row of beads that whizzes along changing the bead positions whenever the picture changes, in this case about three times a second, so the colours appear to move across the screen. If you look closely you can see as colour is changed at the edge of the packet as it moves across the screen.”
“So it’s like an illusion, but doesn’t it take a lot to move all those beads in one go.”
“Well if all the colours changed at once it would be difficult and if we try to change too much at once the animation slows down but for most of the time it's only the beads at the ends of a block of colour that need to be changed.”
She nodded in comprehension but then frowned
“Surely there must be a lot of colours to show, how can you do that with one little bead.”
“Well actually each bead only has six sides, what we call a hexel, each side is either red, green, blue, yellow, black or White. By tilting the colour face we can give the illusion of shade and the beads are so small that by creating clumps of colour mixes we can approximate most colours.”
“Goodness, that must take a lot of working out. How can you do that so fast.”
“We have a high speed difference engine, specifically designed to work with images, that calculates the position and angle of each bead, it works in parallel so that each row of beads gets updates separately but in synchronisation for each picture in the set. And because there are only 6 possible positions to set the bead the time taken to move from one colour to another is extremely fast.”
“That’s incredibly clever but why go to all that trouble when a cine-projector would work as well.”
“Kinematics would only work at night, whereas this screen is visible during the day and thanks to side-lighting can also run at night.”
“It still seems like a lot of effort for an advert. It must cost a fortune to set up and run. Who pays for this.”
“You would be surprised at the amount of money some companies are prepared to pay to use this bill board and not just because it is the talk of the town. Plus we can very quickly and easily change the whole advert in a single second so it is constantly changing. A cine-projector operator would struggle to keep up with that. As soon as the image deck is loaded into the engine hopper we can add a new advert into the run.”
“Well it still seems like a lot of bother when films work so well.”
“Indeed but films also wear out rapidly. After a few days of continuous running, they start to break down and need constant attention and the colours fade. With our system the picture remains the same day after day and if a bead breaks it is usually barely noticeable and can be quickly replaced. I have great hopes that this hexel system will replace old-fashioned film one day, once we have the speed increased to twenty frames a second.”
They both stood there watching the slowly moving image for some time, each contemplating this sign of the times.
