Musings, parallel thoughts
# Image processing
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This is the first in a group of posts, during which I’m going to work through the development of an image processing system. I’m going to start at a very high level working with some classic image processing techniques. The plan as I write this is to work down to a complete implemenation on an FPGA. In the process I’m going to demonstrate how to link the high-level descriptions to check the performance of the low-level FPGA code.
For those who don’t know [Stack Overflow](http://stackoverflow.com/), I recommend having a look round. Web Forums (Fora?) done right. A sensible and easy way of rating questions and answers and questioners and answerers. For the right subjects, a goodly group of knowledgeable people answering them… But mainly on a software theme. Sadly (for me :) FPGAs and HDLs only come up occasionally (but I try and answer when I can). Enter Stack Exchange:
Yet again, Altera make it easy (and cheap – $49!) for people to [play](http://www.altera.com/b/bemicro-sdk.html?WT.mc_id=nm_so_tw_xx_tx_t_371) with their tools:
Altera’s USB development board
Altera’s newest DSP block is quite clearly designed to deal with [double-precision](http://en.wikipedia.org/wiki/Double_precision_floating-point_format) floating-point numbers from the start. They are betting (quite rightly IMHO) that the future is going to move away from pure fixed-point implementations.
If you want to make your own [Drawdio](http://drawdio.com/) without doing any soldering, read on…
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The [Drawdio](http://web.media.mit.edu/~silver/drawdio/) (created by [Jay Silver](http://1derful.org/)) combines drawing with audio. You can get [kits](http://www.ladyada.net/make/drawdio/) to [build one](http://www.makershed.com/ProductDetails.asp?ProductCode=MKAD12), or you can [solder one up on stripboard](http://2ne1.com/drawdio/). But I wanted to make one without faffing with a soldering iron – using screw terminal block.
That counts out the use of integrated circuits like the 555 variants used in the traditional Drawdio…
Just upgraded my desktop from 9.04 to 10.04LTS. I’d skipped 9.10 because of the [Intel graphics shenangigans](http://ubuntuforums.org/showthread.php?t=1130582) – there’s 133 pages to that thread – gives some idea of the level of aggro that seemed to be involved!
And today’s upgrade died horribly part way through with dependencies it couldn’t sort out…
Control engineers know that non-linearity causes problems – the rest of the world could maybe take note…
Comments in code are very useful. But not as good as executable comments…
We found a load of polystyrene in the garage this afternoon, so we decided to make a [hot-wire cutter](http://en.wikipedia.org/wiki/Hot-wire_foam_cutter) for it. Basically, you take some wire with an ohm or two resistance and pass a few amps of current through it. The wire is held tight and the polystyrene melts as it passes around the wire.