使用GD库对水印进行全宽和全高

Question

Alright so I am trying to set this watermark to full width and height so it fills the image but for some reason it keeps popping up in its original size only.

So basically instead of stretching the watermark to fit the image, not it just places the watermark in the middle of the image...

    function watermark($sourcefile, $watermarkfile) {

    #
    # $sourcefile = Filename of the picture to be watermarked.
    # $watermarkfile = Filename of the 24-bit PNG watermark file.
    #

    //Get the resource ids of the pictures
    $watermarkfile_id = imagecreatefrompng($watermarkfile);

    imageAlphaBlending($watermarkfile_id, false);
    imageSaveAlpha($watermarkfile_id, true);

    $fileType = strtolower(substr($sourcefile, strlen($sourcefile)-3));

    switch($fileType) {
        case('gif'):
            $sourcefile_id = imagecreatefromgif($sourcefile);
            break;

        case('png'):
            $sourcefile_id = imagecreatefrompng($sourcefile);
            break;

        default:
            $sourcefile_id = imagecreatefromjpeg($sourcefile);
    }

    //Get the sizes of both pix   
  $sourcefile_width=imageSX($sourcefile_id);
  $sourcefile_height=imageSY($sourcefile_id);
  $watermarkfile_width=imageSX($watermarkfile_id);
  $watermarkfile_height=imageSY($watermarkfile_id);

    $dest_x = ( $sourcefile_width / 2 ) - ( $watermarkfile_width / 2 );
    $dest_y = ( $sourcefile_height / 2 ) - ( $watermarkfile_height / 2 );

    // if a gif, we have to upsample it to a truecolor image
    if($fileType == 'gif') {
        // create an empty truecolor container
        $tempimage = imagecreatetruecolor($sourcefile_width,
                                                                            $sourcefile_height);

        // copy the 8-bit gif into the truecolor image
        imagecopy($tempimage, $sourcefile_id, 0, 0, 0, 0, 
                            $sourcefile_width, $sourcefile_height);

        // copy the source_id int
        $sourcefile_id = $tempimage;
    }

    imagecopy($sourcefile_id, $watermarkfile_id, $dest_x, $dest_y, 0, 0,
                        $watermarkfile_width, $watermarkfile_height);

    //Create a jpeg out of the modified picture
    switch($fileType) {

        // remember we don't need gif any more, so we use only png or jpeg.
        // See the upsaple code immediately above to see how we handle gifs
        case('png'):
            header("Content-type: image/png");
            imagepng ($sourcefile_id);
            break;

        default:
            header("Content-type: image/jpg");
            imagejpeg ($sourcefile_id);
    }           

    imagedestroy($sourcefile_id);
    imagedestroy($watermarkfile_id);

}

Answer 1

Use imagescale to sclae your watermark image to the same size as your source image and then use imagecopy :

$scaled_id = imagescale($watermarkfile_id, $sourcefile_width, $sourcefile_height);
imagecopy($sourcefile_id, $scaled_id, 0, 0, 0, 0, $watermarkfile_width, $watermarkfile_height);