Creating Custom Color Palette from Image

Suppose you have an image that was created in another package, and you would like to replicate the color palette used in the image within EnSight? Well, EnSight can easily accept custom Color Palettes (see UserManual). The only “tough” part is getting from original image file the RGB values used and into a form of the EnSight Color Palette (.cpal) file. Well, guess what, Python (and more specifically EnVe) can be used to grab out the color legend information, and create your own color palette file (.cpal) for EnSight.

So, how you go about doing this:

1. Start with an image created in another package, which has a color legend. Crop the image to just the color legend palette. You now have an image file which has (in this example) a vertical specification of the color palette.

2. Use the attached python routine below on this file image file. This python routine uses EnVe to query the image file for the RGB values of the pixels in the image, and grab those values off, and write out an EnSight Color Palette file (.cpal) with the appropriate information in it. (If your image has a horizontal legend, then you can switch the x,y values around to perform the same operation).

3. You can thus create a new EnSight Color Palette File (.cpal) from the original image created in another package. EnSight has a limit of 21 bands, but handles 16 colors per band for smooth palette range.

 

As always, please contact us here at CEI should you have any questions, comments, having trouble, or would like routines this customized to your needs. We are here to help.

Click here for Color Palette Create Tool