完全なクレジットは次のとおりです:
http://consistentcoder.com/combine-a-transparent-png-image-on-top-of-another-image-with-php
次のコードは、オーバーレイの透明度を維持しながら、前景画像を背景画像にオーバーレイします。
//set the source image (foreground)
$sourceImage = 'table.png';
//set the destination image (background)
$destImage = 'create-a-surreal-head-of-tree-photo-manipulation.jpg';
//get the size of the source image, needed for imagecopy()
list($srcWidth, $srcHeight) = getimagesize($sourceImage);
//create a new image from the source image
$src = imagecreatefrompng($sourceImage);
//create a new image from the destination image
$dest = imagecreatefromjpeg($destImage);
//set the x and y positions of the source image on top of the destination image
$src_xPosition = 75; //75 pixels from the left
$src_yPosition = 50; //50 pixels from the top
//set the x and y positions of the source image to be copied to the destination image
$src_cropXposition = 0; //do not crop at the side
$src_cropYposition = 0; //do not crop on the top
//merge the source and destination images
imagecopy($dest,$src,$src_xPosition,$src_yPosition,
$src_cropXposition,$src_cropYposition,
$srcWidth,$srcHeight);
//output the merged images to a file
/*
* '100' is an optional parameter,
* it represents the quality of the image to be created,
* if not set, the default is about '75'
*/
imagejpeg($dest,
'combine-a-transparent-png-image-on-top-of-another-image-with-php-01.jpg',
100);
//destroy the source image
imagedestroy($src);
//destroy the destination image
imagedestroy($dest);