Adjust opacity/transparency of image

[moldach]

I would like to overlay two images with image_mosaic() where one of the images is 50% transparent.

I was able to find a solution that works using the CLI but I'm not sure what the appropriate (if any) solution would be in magick r version?

For example, the following solution at this website works for me:

magick convert images/qrcode.png -alpha set -background none -channel A -evaluate multiply 0.420 +channel images/qrcode.png

I'm able to overlay a QR code on top a image that allows me to still scan that image.

[dcaud]

Something like this overlays with transparency:

wizard %>%
  image_composite(rose, operator = "dissolve",compose_args = "80%",
                  gravity="center")