Replace transparency in PNG images with white background

Question

I\'ve got some PNG images with transparency, and I need to create versions with the image layer composed onto a white background. I\'ve tried various things with Image Magi

Answer 1

Using -flatten made me completely mad because -flatten in combination with mogrify crop and resizing simply doesn't work. The official and for me only correct way is to "remove" the alpha channel.

-alpha remove -alpha off (not needed with JPG)

See documention: http://www.imagemagick.org/Usage/masking/#remove

Answer 2

It appears that your command is correct so the problem might be due to missing support for PNG (). You can check with convert -list configure or just try the following:

sudo yum install libpng libpng-devel

Answer 3

This works for me:

convert -flatten img1.png img1-white.png

Documentation references:

• -flatten command-line option
• -layers command-line option (-flatten is equivalent to -layers flatten)

Answer 4

The only one that worked for me was a mix of all the answers:

convert in.png -background white -alpha remove -flatten -alpha off out.png