I have a bit of an issue using PIL (python image library) when trying to Image.blend a mask (solid colour image with transparent corners) onto an existing image. It seems that the result applies the transparencies in the corners loosing the original image content. I want the original image content left intact, as it was before the blend.
I've attached the 2 images I am blending and the resultant output. "img.jpg" is the main image, "mask.png" is the mask img. The mask is actually rendered in code using ImageDraw arc functions etc, but to demonstrate I saved a png from it in code and am using the resultant file here.
The simple code to generate the output looks like this:
I have tried converting the png to RGB and the jpg to RGBA for the blend, either way I get the same result.
from PIL import Image
mask = Image.open("/tmp/mask.png")
img = Image.open("/tmp/img.jpg")
img = img.convert("RGBA") #convert to same mode as mask for blend...
#mask = mask.convert("RGB") #convert to same mode as img for blend...
print "\npre blend:"
# apply mask to background image
img = Image.blend(img, mask, 0.5)
print "\npost blend:"
Any one got any ideas on how to achieve the result I am after? I need the mask to apply on all the image bar the corner pieces...
Any alternative suggestions on how to do this in code are welcome too, maybe I have chosen the wrong method? Does PIL just not handle overlaying transparencies onto an image? If I paste on top I lose the image behind even if the top image has some opacity.