Convert PNG to JPG and set transparent background to white with ImageMagick and PHP

Question

How can I use ImageMagick (with the php extension) to set the transparent background to white when converting an image from PNG to JPEG?

Answer 1

At time of writing, you have not specified which extension you are using, but if you were using the commandline, the command would be:

convert image.png -background white -flatten -alpha off image.jpg

More information can be found on the Masking Usage documentation.

Using IMagick for instance, I think you could do this as follows:

(totally untested, never used IMagick and don't have it installed to test)

$image = new IMagick('image.png');

$flattened = new IMagick();
$flattened->newImage($image->getImageWidth(), $image->getImageHeight(), new ImagickPixel("white"));

$flattened->compositeImage($image, imagick::COMPOSITE_OVER, 0, 0);

$flattened->setImageFormat("jpg");
$flattened->writeImage('image.jpg');

$image->clear();
$image->destroy();
$flattened->clear();
$flattened->destroy();