Advanced Image Editing Under the GD Library Page 4

Translucent Text

Translucent text is not as simple as outlining or shadowing, but it’s not particularly hard. A translucent image is just something partially invisible, or clear. This is done by drawing the image onto a buffer, editing the buffer, and then merging the buffer back onto the original image.

<?php
function imagettftexttransparent(&$im,$size,$angle,$x,$y,&$col,$fontfile,$text,$pct) {
    $im_w = imagesx($im); // Get the image width
    $im_h = imagesy($im); // Get the image height
    $new = imagecreate($im_w,$im_h); // Create a buffer
    imagesetpixel($im,$im_w-1,0,$col); // Set a pixel down, so we can easily get the color
    $index = imagecolorat($im,$im_w-1,0); // Get the color at that pixel
    $rgb = imagecolorsforindex($im,$index); // Get the index of that color
    $r = $rgb["red"]; // Get the red value
    $g = $rgb["green"]; // Get the green value
    $b = $rgb["blue"]; // Get the blue value
    $color = imagecolorallocate($new,$r,$g,$b); // Allocate this color on the buffer
    $copy = imagecopy($new,$im,0,0,0,0,$im_w,$im_h); // Copy the old image onto the buffer
    $text = imagettftext($new,$size,$angle,$x,$y,$color,$fontfile,$text); // Draw the text
    $merge = imagecopymerge($im,$new,0,0,0,0,$im_w,$im_h,$pct); // Copy the buffer back onto the original image
    imagedestroy($new); // Destroy the buffer
}
?>

Anything that was on the image before stays where it was, untouched. The only difference is that text appears over the image now. This example places text over a metallic panel: