waveform display in browser

Those sections are talking about the color table. The index is still a maximum of 8 bits, because it's defined by the 3 bit value (which stores the exponent-1).

I thought that your original claim was that each pixel has 3 colours independent of any table, but I think I misinterpreted you and we've been talking past each other. Sorry about that.

I guess the only format I ever worked with in TIFF was the run-length encoduing used by faxes. I had forgotten there were other options for compression.

It's good to hear that SVG support is common enough to be useful.

The last time I needed to do data plots on web pages was something like 6-7 years ago, and SVG was a bit too bleeding edge at the time.

Blocking flash (with an optional white-list) is absolutely essential to making the 'web a useful place. Unless it's a site providing someting I desperately need, I usually just completely avoid web sites that require flash to get something done.

just serve up flot and poll the data from a json file

-Lasse

finding the information is only part of the problem, YOU also need to understand it.

That pretty-much as I remember it from the early 90s.

hmm, seaction 19 and section 21. say something very similar to 3*2^N

1. Table Based Image Data. "LZW Minimum Code Size" see appendix F for it's significgance starting at "ESTABLISH CODE SIZE" what it means is that the actual data is N-bit indices into the color table, because indices 2^N and above cannot be coded.

if that's too complicated, see this part ot the wikipedia page:

So this just sends the data and the web page itself generates the plot?

ate

yes, it read the data points etc. from a json file (just a text file in spe cific format) and generates the plot from that

-Lasse

yeah, you send a bunch of co-ordinates (typically ascii base-10 numbers) and it draws the lines, this is fairly wasteful of bandwidth, (compared to .WAV fromat) but that can be partially remidied using gzip compression at the server end, OTOH compression is probably not needed for this application.

One of my guys threw this together pretty fast:

It uses javascript to generate a sine wave and pushes SVG into the browser to plot it. Seems fine under Firefox. It's only 250 points and looks pretty good.

It doesn't look hard to have my tachometer box digitize waveforms (AD7276 maybe) and display in the browser, without loading any apps or anything.

Nice. I'll have to toss that into my EM simulator at some point.

Cheers

Phil Hobbs