How to watermark images automatically

Question

I want to add watermark to my users images posts automatically.

I've done below code already, but the images become Blank with watermark.

Blank Image: https://drk3g4xn3fsso.cloudfront.net/1503319365_b6ffc731d32b4abc1503319361869.jpg

<?php

function resizeimage($img,$size){
    $width=$size[0];
    $height=$size[1]; 
    $newwidth = 640;
    $newheight = $height*($newwidth/$width);
    $tci = imagecreatetruecolor($newwidth, $newheight);
    imagecopyresampled($tci, $img, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
    return $tci;
}

function startsWith($haystack, $needle)
    {
         $length = strlen($needle);
         return (substr($haystack, 0, $length) === $needle);
    }

function compress($source, $destination, $quality,$add_watermark=FALSE) {

    $info = getimagesize($source);

    if ($info['mime'] == 'image/jpeg') 
        $image = imagecreatefromjpeg($source);

    elseif ($info['mime'] == 'image/gif') 
        $image = imagecreatefromgif($source);

    elseif ($info['mime'] == 'image/png') 
        $image = imagecreatefrompng($source);

    $image=resizeimage($image,$info);

    if ($add_watermark){
        $watermark=imagecreatefrompng("watermark.png");
        $infoWatermark=getimagesize("watermark.png");
        $imageWidth=$info[0];
        $imageHeight=$info[1];
        $watermarkWidth=$infoWatermark[0];
        $watermarkHeight=$infoWatermark[1];

        //imagecopyresampled($image,$watermark,20,20,0,0,$watermarkWidth,$watermarkHeight,$watermarkWidth,$watermarkHeight);
        imagecopy($image,$watermark,20,20,0,0,$watermarkWidth,$watermarkHeight);
    }

    imagejpeg($image, $destination, $quality);

    return $destination;
}

I just wonder what I've done wrong to make it not work with the uploaded image?

thank you.

Answer 1

Hello here is the demo to generate image with Watermark.

Folder Structure :

Demo

• upload/sample.jpg
• index.php
• watermark.png

Note : watermark.jpg is the image which you use as watermark on sample.jpg image.

Here is the index.php code.

<?php

if(isset($_FILES['image_file']))
{
    $max_size = 800; //max image size in Pixels
    //$destination_folder = 'D:/Websites/watermark/images';
    $watermark_png_file = 'watermark.png'; //watermark png file

    $image_name = $_FILES['image_file']['name']; //file name
    $image_size = $_FILES['image_file']['size']; //file size
    $image_temp = $_FILES['image_file']['tmp_name']; //file temp
    $image_type = $_FILES['image_file']['type']; //file type

    switch(strtolower($image_type)){ //determine uploaded image type 
            //Create new image from file
            case 'image/png': 
                $image_resource =  imagecreatefrompng($image_temp);
                break;
            case 'image/gif':
                $image_resource =  imagecreatefromgif($image_temp);
                break;          
            case 'image/jpeg': case 'image/pjpeg':
                $image_resource = imagecreatefromjpeg($image_temp);
                break;
            default:
                $image_resource = false;
    }

    if($image_resource){
        //Copy and resize part of an image with resampling
        list($img_width, $img_height) = getimagesize($image_temp);

        //Construct a proportional size of new image
        $image_scale        = min($max_size / $img_width, $max_size / $img_height); 
        $new_image_width    = ceil($image_scale * $img_width);
        $new_image_height   = ceil($image_scale * $img_height);
        $new_canvas         = imagecreatetruecolor($new_image_width , $new_image_height);

        if(imagecopyresampled($new_canvas, $image_resource , 0, 0, 0, 0, $new_image_width, $new_image_height, $img_width, $img_height))
        {

            //center watermark
            $watermark_left = ($new_image_width/2)-(300/2); //watermark left
            $watermark_bottom = ($new_image_height/2)-(100/2); //watermark bottom

            $watermark = imagecreatefrompng($watermark_png_file); //watermark image
            imagecopy($new_canvas, $watermark, $watermark_left, $watermark_bottom, 0, 0, 300, 100); //merge image

            //output image direcly on the browser.
            header('Content-Type: image/jpeg');
            imagejpeg($new_canvas, NULL , 90);

            //Or Save image to the folder
            imagejpeg($new_canvas,'uploads/'.$image_name , 90);

            //free up memory
            //imagedestroy($new_canvas); 
            //imagedestroy($image_resource);
            //die();
        }
    }
}

?>
<!DOCTYPE HTML>
<html>
<head>
<style type="text/css">
#upload-form {
    padding: 20px;
    background: #F7F7F7;
    border: 1px solid #CCC;
    margin-left: auto;
    margin-right: auto;
    width: 400px;
}
#upload-form input[type=file] {
    border: 1px solid #ddd;
    padding: 4px;
}
#upload-form input[type=submit] {
    height: 30px;
}
</style>
</head>
<body>

<form action="" id="upload-form" method="post" enctype="multipart/form-data">
<input type="file" name="image_file" />
<input type="submit" value="Send Image" />
</form>

</body>
</html>