I’ve been struggling with trying to apply a gradient map which is sourced from an image file to a grayscale image which includes alpha/transparency. The following includes the source image and the gradient map image. I first attempted this with numpy and was unsuccessful. The purpose of this is to be able to programmatically color image layers using gradient maps. Any help would be appreciated. Thank you!
from PIL import Image gray, alpha = Image.open(source_fn).convert('LA').split() gradient = Image.open(gradient_fn).convert('RGB').resize((256, 1)) lut =  for band in gradient.split(): lut += list(band.getdata()) out = gray.point(lut, 'RGB') out.putalpha(alpha) out.save(out_fn, 'PNG')
Here’s the result. It doesn’t quite match the example you provided as the intended result, but I think that’s just a misunderstanding of how the range of inputs were supposed to map to the gradient. I’m sure you could fix that yourself.
Answered By – Mark Ransom
Answer Checked By – Dawn Plyler (AngularFixing Volunteer)