[Tioga-users] monochrome image

[Sergey Astanin]

Hello!

> But I'm actually only interested if the value is above or below 0 and want
> to plot everything above 0 grey and keep everything else white. I think I
> need the create_monochrome_image_data for that but can't figure it out.

I think they may be done with custom colormap, something like this:

bicolor_colormap = t.create_colormap(
        'length' => 4,
        'points' => [ 0.0, 0.5-1e-99, 0.5+1e-99, 1.0 ],
        'Rs' => [ 0.3, 0.3, 1.0, 1.0 ],
        'Gs' => [ 0.3, 0.3, 1.0, 1.0 ],
        'Bs' => [ 0.3, 0.3, 1.0, 1.0 ]
)

and use it in t.show_image. This way you could make one half of the image
range appear in gray (rgb:0.3,0.3,0.3), and the other half in white
(rgb:1.0,1.0,1.0), with very narrow transition region. Choosing
'min_value' and 'max_value' symmetrically would place this transition
region in data's zero.

However, I have not tried plotting bicolor images. Let us know if it
works. My use case seems to be close to yours.

Best regards,
Sergey Astanin.