Live Video Scaling
JWB80
Posts: 5
I would like to interface a color camera such as the C328 to the prop. Have it bring in the video scale it horizontally and vertically (larger and/or smaller) then adjust where on the output (vga/composite) it's displayed. I'd have 2 pots for the zoom/scale (1 for hor 1 for vert) 2 for the position of the output (1 for hor and 1 for vert). Last would be 2 pots for brightness and contrast. This will basically be like the adjustments on your monitor only for a camera. Anyone that can help will be compensated once this becomes a marketable product.
Comments
If you could feed the signal to all the Props and have each Prop process only one line, could the signal be "put back together" and displayed?
I'm sure this is a very awkward and probably expensive way of doing it. But I do wonder if it would be possible.
Duane
http://www.4dsystems.com.au/prod.php?id=75
The video stream there is at a low res (128x128) and frame rate. This will give you some idea of what might be achievable through a serial link. Perhaps this is adequate for your application? 160x120x1byte/pixel (colour or grey) would use 58% of the props hub memory.
Does the zoom need to be continuous or could it jump to integer magnifications (1x, 2x, 3x etc) ?
Then all you'd have to do is have a serial cog to read the data, and another cog to decode the jpg, if you use the camera's 80x60 output, then it would probably decode the jpg rather quickly in pasm. depends on what image resolution you were wanting.
So yes, it is possible on a single prop, but it would be low resolution.
1x-5x would work in half increments controlled by a pot
1. You are going to want to have as little latency as possible. So the less processing done at each stage the better.
2. You have three main components: the camera which provides the input, the glasses for output and some kind of processor between them. The processor needs to interface with the input and output components, transform the data as required, and implement the scaling.
3. What kind of interface do the glasses have (VGA or composite, analog or digital) and what resolution? The Prop's video output is great, if somewhat limited. Because your are scaling horizontally you don't need to buffer an entire frame, just a line or two.
4. The camera output is the real challenge. The Propeller doesn't have the ability to digitize video at a decent rate so ideally this would be done by the camera component. But then that data has to be streamed to the Propeller. It would also be easier if the camera output matches the glasses input so you don't have to do any colorspace conversions.
It may even be possible to accomplish your task without a dedicated processor. Back in the late 80s / early 90s I did some digital video filtering using a FIR filter chip and a FIFO as a line buffer with some EPROMs to generate the sync data. So slurp in the line then spit it back out twice as fast and generate blank to sync.
Could you physical hack the monitor glasses and move the entire screen so it was in her field of view?
I also wonder if there is an optical solution. When my brother was in traction for several weeks, he used some prism glasses that allowed him to watch TV and read a book without having to have the TV on the ceiling or having to hold the book up in front of his face. Could some combination of mirrors, prisms and lenses be made to accomplish the results you're after?
Duane