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).


bilinear.png:
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bilinear2.png:
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[Warren Massey]

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.

[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.

[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.

[Ben]

Please post the code as you are using it.
We are much better with visual aides.
 
Ben

[codas]

NI suport said, it should be a problem of color depth or a driver probelm. They can not reproduce the problem. I'm using:
SuSE Linux 8.2
Color depth: 16 Bit (65536 colors)
User Interface: KDE 3.1.1


IntensityGraph256Markers.png:
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setMarkerValues.vi:
http://forums.ni.com/attachments/ni/170/156225/2/setMarkerValues.vi


IntensityGraph001Markers.png:
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[Warren Massey]

The VI works fine using Windows XP. See the attached picture.
 


IntensityGraph256Markers-WinXP-16-bit_display.png:
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