[Image-SIG] TIFF16 greyscale to color image

[Fredrik Lundh]

Stephane Henry wrote:

> Could someone point me an efficient way to transform 16 bits
> greyscale tiffimage to a color image; or more simply how to create a
> color image from an array of value with the possibility to choose the
> palette, like the function imshow from Matplotlib.

quick recipe:

- use getextrema to get the min/max value for the image (unless already
  known)

- use point to translate the image down to an "L" image; you can use either
  a the argument*scale+offset form, or a 64k lookup table:

        http://effbot.org/imagingbook/image.htm#Image.point

- use putpalette to attach a palette to the L image:

        http://effbot.org/imagingbook/image.htm#Image.putpalette

- if necessary, convert back to RGB.

</F>