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Topic: Curves and Exposure (Read 442 times) |
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jbk303
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Curves and Exposure
« on: Nov 17th, 2003, 5:46am » |
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Two unrelated questions:
Walking along the street, I happened upon a record shop. It reminded me of, for reasons that should be obvious, music. I like music. A lot. And so I considered note structures, thinking the way I do, and how they are connected. With some tweaking, a MIDI file could be turned into the nodes and edges of a graph. I want to do so, but to make it pretty I also want curves between the notes showing their the connections with thicknesses reflecting the number of times a note transition is made. Any good code or algorithms to draw these curves? (and MIDI file stuff too? I'm pretty iggerant about that as well.)
When I scan with my scanner, the scan program can adjust the exposure of the scan. (Scan, scan, scan. Sorry.) It shows a kick-buns histogram and stuff. You can adjust the high, low, and middle color amounts which lets you do really awesome stuff to the pictures. How is this done? I would love to add the effect to a sketch or really just know how it works.
Please feel free to respond to only one (or none, I guess ) of my sub-posts.
Thanks in advance,
Josh
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toxi
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Re: Curves and Exposure
« Reply #1 on: Nov 17th, 2003, 6:01pm » |
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re:adjusting colour levels, below is a little demo to independently adjust the RGB levels of a picture.
http://www.toxi.co.uk/p5/levels/
just press R, G or B to select a channel and then draw in the picture to change the curves. these curves represent a simple conversion table for each intensity level of the 3 channels. the horizontal axis stands for the input intensity (further right = higher values), the vertical one stands for the output (further up = higher values). by default the curves are linear, so that they represent a 1:1 match. e.g. 10% red as input will result in 10% red output. but you can totally twist things around if you change the tables to produce a 100% red for a 10% input. just doodle around a bit with the mouse, you'll get the drift...
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http://toxi.co.uk/
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jbk303
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Re: Curves and Exposure
« Reply #2 on: Nov 17th, 2003, 6:55pm » |
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That is exactly what I was talking about. Thanks a ton. I couldnt find any info anywhere else. Awesome sketch, too. Nice interface.
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