Unable to remove transparency when converting PDF to TIFF

[bmoscon]

Using the following code:

from wand.image import Image, Color


with Image(filename='5-page-pdf.pdf', resolution=200, colorspace='gray', background=Color('white')) as img:
    img.type = "grayscale"
    img.format = "tiff"
    img.compression = "lzw"
    img.alpha_channel = 'off'
    img.save(filename="test.tiff")

I get a TIFF that has transparency enabled on pages 2-4. I've tried other things to remove the alpha channel ('remove', using a context manager on the sequence to remove it on the individual SingleImages, etc), but nothing seems to work. I've pasted links to the original PDF and the TIFF this produces.

I should note that imageMagick has no issues when I use the following command:

convert -density 200 5-page-pdf.pdf -type grayscale -compress lzw test.tiff

So I'm not sure if this is a bug in wand or something else.
PDF
TIFF

[emg36]

I have come across a similar bug.

On MacOS to remove transparency from .pngs I need to set img.alpha_channel = 'remove' and in a linux environment I need to set img.alpha_channel = False.

[emcconville]

Thanks for opening an issue here, as well as posting on stackoverflow. It really helps folks search for similar issues.

Additional test case posted by Fred.

for frame in img.sequence:
    img.background_color = "white"
    img.alpha_channel = "remove"