PHP Image plus watermark principle (super Simple instance code) _php technique

Text watermark:

Copy Code code as follows:

$w = 80;
$h = 20;
$im = Imagecreatetruecolor ($w, $h);
$textcolor = Imagecolorallocate ($im, 123, 12, 255);
$white = Imagecolorallocate ($im, 255, 255, 255);
$grey = Imagecolorallocate ($im, 128, 128, 128);
$black = imagecolorallocate ($im, 0, 0, 0);
Imagefilledrectangle ($im, 0, 0, 399, $grey); Draw a rectangle and fill

Write the string in the upper-left corner of the image
Imagestring ($im, 3, 2, 3, "Hello world!", $textcolor);

Output image
Header ("Content-type:image/jpeg");
Imagejpeg ($im);
Imagedestroy ($im);

Picture watermark

$GROUNDIMG = "Dsc05940.jpeg";
$groundInfo = getimagesize ($GROUNDIMG);
$ground _w = $groundInfo [0];
Print_r ($groundInfo);
$ground _h = $groundInfo [1];
Switch ($groundInfo [2]) {
Case 1:
$ground _im = imagecreatefromgif ($GROUNDIMG);
Break
Case 2:
$ground _im = Imagecreatefromjpeg ($GROUNDIMG);
Break
Case 3:
$ground _im = imagecreatefrompng ($GROUNDIMG);
Break
}

$WATERIMG = "Dsc05949.jpeg";
$imgInfo =getimagesize ($WATERIMG);
$water _w = $imgInfo [0];
$water _w = $imgInfo [1];

Switch ($imgInfo [2]) {
Case 1:
$water _im = imagecreatefromgif ($WATERIMG);
Break
Case 2:
$water _im = Imagecreatefromjpeg ($WATERIMG);
Break
Case 3:
$water _im = imagecreatefrompng ($WATERIMG);
Break
}
Imagecopy ($ground _im, $water _im,100,100,0,0,500,500);
Header ("Content-type:image/jpeg");

Imagejpeg ($ground _im);

Merging pictures PHP provides a number of functions: for example: imagecopymerge,imagecopyresized