Add "color bar" look-up table option to Colormap module

[jywarren]

Let's:

1. rename the segmented-colormap module to simply colormap and
2. get it to optionally overlay a 0-100% reference color bar to show the color mapping we're using, as in the above example

The first version need not show the numeric range, which currently would be only 0-255 as per the module notes: https://github.com/publiclab/image-sequencer/blob/master/src/modules/SegmentedColormap/SegmentedColormap.js

Follow-up issues could be:

1. to allow setting the range to values other than 0-255 with an options.range = [low, high] setting
2. displaying the low and high range values on the colorbar itself, although this would require the ability to write text, which we don't currently have (Various module ideas to be broken out into separate issues #165)

[jywarren]

GitMate.io thinks possibly related issues are #52 (segmented-colormap module), #157 (Add a Contrast module), #97 (Add module options to CLI), #158 (Add a Saturation Module), and #27 (add fisheyegl module).

[jywarren]

Here's a good reference for how to convert a min and max value into a colorbar using a colormap function like we have:

https://github.com/publiclab/infragram/blob/eb9fc19f993616caf9aa0311f7468d33c4529253/src/processors/javascript.js#L135-L154

colorbar could in fact be its own module which we call from here -- accepting an x,y location to draw the colorbar and the min,max and colorize() functions -- it's all nice and modular :-)

[marzann]

@jywarren, could you include a webpage link where the color bar would be added?

[jywarren]

Like, the button or link which would cause it to be generated? Sorry, maybe I don't quite understand? Thank you!!!!

…

On Sun, Apr 29, 2018 at 11:27 AM, Marzanna ***@***.***> wrote: @jywarren <https://github.com/jywarren>, could you include a webpage link where the color bar would be added? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#222 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AABfJw1rgc2rHLCWaU1cTEFlxg7x1sClks5ttdvwgaJpZM4Trj59> .

[marzann]

I would like to confirm 2 items:

1. the file to work on
2. the page url to test it :)

[jywarren]

Oh i'm so sorry i missed this comment! If you're still interested perhaps we can pick back up here or in another issue?

I'm chiming in with a link to a colormapping lib I found: https://github.com/santilland/plotty