How to create a smooth color ramp for Intensity Charts/Graphs

[codas]

How can I create a smooth color ramp for Intensity Charts (Pic: bilinear.png). By default I only get about 10 colors and it uses the same color for a big range of values (Pic: bilinear2.png).

[WNM]

If you go to your front panel and right-click on the intensity graph color ramp is the "interpolate colors" option checked?

It should be. Then all you need to do is to (as a minimum) specify the "high color" and the "low color" to define the ramp.

[codas]

That's exactly what I did. 'Interpolate colors' option is checked. Specifying the 'high color' and the 'low color' creates a bar with the specified colors at the top and bottom position in the color ramp, but nothing else. Reading the 'Color Table' I get an array with 256 different colors. But the ramp only shows about 10 colors. I'm using LabVIEW 7.1 for Linux.

[becktho]

This sounds maybe a bit silly - but did you check the values you wired to the graph?

If you just have ten different values, you will just see ten different colours.

[codas]

I just play arround with variations of the example 'Bilinear_interpolation.vi' by Christian Altenbach postet in the 'Interpolating pixels in the Intensity Graph ' thread. This example generates an 40x40 array with about 1600 different Values between 0 and 12. The result I get is shown in the 'bilinear2.png' I postet in the first message.

[becktho]

Which colours does the colortable display? There you can see the whole colour range which is use by the graph.

[codas]

The Colortable shows 255 different Colors from black over blue to white. I already changed this to other color tables like given in the Example 'Common Intensity Maps.vi' (LV Example Finder). I never get a smooth color ramp.

[becktho]

That's strange. Unfortunately I can't reproduce this behaviour, as I use LV7.0 on Windows platforms.

I'd suggest to search the forums once more (maybe more with focus on linux) and, if not successful, contact NI.

[WNM]

I'm on a Windows system and know next-to-nothing about Linux so I don't know how much use I'll be to you but is it possible that this might have something to do with your video display system, driver or interface and how they are setup? It would seem to me that LabVIEW at least thinks that it has 256 colors to display.

[codas]

I would say, that my display system handles about 65536 (16 bit) different colors and this is equal to 256*256. This shouldn't be the problem.