How can I identify images with a dominant color of white but ignoring the alpha channel in the calculation?

I need to do exactly this post. I need to identify images with a dominant color of white.

I've tried the answer in the question I referenced above:

magick image -fuzz 1% -fill white -opaque white -fill black +opaque white -scale 1x1 -format "%[fx:100*mean]\n" info:

However my images have an alpha channel and it seems that is being taken into consideration during the calculation because the result I'm getting is 25 despite the image being pure white with transparency.

Here are a couple example images (Note, they will look invisible since it's on a white background, but the images are in-fact there):

Can someone help me identify white images while ignoring transparency in the mean calculation?

Really appreciate any help.

Turn the alpha channel off and use 1x1! (note the ! mark) in Imagemagick.

magick white.png -alpha off -fuzz 1% -fill white -opaque white -fill black +opaque white -scale 1x1! -format "%[fx:100*mean]\n" info:

91.9187

or

magick white.png -alpha off -fuzz 1% -fill white -opaque white -fill black +opaque white -scale 1x1! -format "%[fx:100*u]\n" info:

91.9187

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I note that your white image has black in the base rgb image and also in the alpha channel. Perhaps you should make the base image perfectly white.

magick white.png -background white -alpha background -scale 1x1! -alpha off -format "%[fx:100*mean]\n" info:

99.9999