I'm using Nihilogic's "Canvas2Image" JavaScript tool to convert canvas drawings to PNG images. What I need now is to turn those base64 strings that this tool generates, into actual PNG files on the server, using PHP.
In short, what I'm currently doing is to generate a file on the client side using Canvas2Image, then retrieve the base64-encoded data and send it to the server using AJAX:
// Generate the image file
var image = Canvas2Image.saveAsPNG(canvas, true);
image.id = "canvasimage";
canvas.parentNode.replaceChild(image, canvas);
var url = 'hidden.php',
data = $('#canvasimage').attr('src');
$.ajax({
type: "POST",
url: url,
dataType: 'text',
data: {
base64data : data
}
});
At this point, "hidden.php" receives a data block that looks like data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAABE...
From this point on, I'm pretty much stumped. From what I've read, I believe that I'm supposed to use PHP's imagecreatefromstring function, but I'm not sure how to actually create an actual PNG image from the base64-encoded string and store it on my server. Please aid!
This question is related to
php
javascript
base64
html5-canvas
Taken the @dre010 idea, I have extended it to another function that works with any image type: PNG, JPG, JPEG or GIF and gives a unique name to the filename
The function separate image data and image type
function base64ToImage($imageData){
$data = 'data:image/png;base64,AAAFBfj42Pj4';
list($type, $imageData) = explode(';', $imageData);
list(,$extension) = explode('/',$type);
list(,$imageData) = explode(',', $imageData);
$fileName = uniqid().'.'.$extension;
$imageData = base64_decode($imageData);
file_put_contents($fileName, $imageData);
}
It's simple :
Let's imagine that you are trying to upload a file within js framework, ajax request or mobile application (Client side)
Here how to do it using PHP
<?php
$base64String = "kfezyufgzefhzefjizjfzfzefzefhuze"; // I put a static base64 string, you can implement you special code to retrieve the data received via the request.
$filePath = "/MyProject/public/uploads/img/test.png";
file_put_contents($filePath, base64_decode($base64String));
?>
I had to replace spaces with plus symbols str_replace(' ', '+', $img); to get this working.
Here is the full code
$img = $_POST['img']; // Your data 'data:image/png;base64,AAAFBfj42Pj4';
$img = str_replace('data:image/png;base64,', '', $img);
$img = str_replace(' ', '+', $img);
$data = base64_decode($img);
file_put_contents('/tmp/image.png', $data);
Hope that helps.
Well your solution above depends on the image being a jpeg file. For a general solution i used
$img = $_POST['image'];
$img = substr(explode(";",$img)[1], 7);
file_put_contents('img.png', base64_decode($img));
based on drew010 example I made a working example for easy understanding.
imagesaver("data:image/jpeg;base64,/9j/4AAQSkZJ"); //use full base64 data
function imagesaver($image_data){
list($type, $data) = explode(';', $image_data); // exploding data for later checking and validating
if (preg_match('/^data:image\/(\w+);base64,/', $image_data, $type)) {
$data = substr($data, strpos($data, ',') + 1);
$type = strtolower($type[1]); // jpg, png, gif
if (!in_array($type, [ 'jpg', 'jpeg', 'gif', 'png' ])) {
throw new \Exception('invalid image type');
}
$data = base64_decode($data);
if ($data === false) {
throw new \Exception('base64_decode failed');
}
} else {
throw new \Exception('did not match data URI with image data');
}
$fullname = time().$type;
if(file_put_contents($fullname, $data)){
$result = $fullname;
}else{
$result = "error";
}
/* it will return image name if image is saved successfully
or it will return error on failing to save image. */
return $result;
}
One-linear solution.
$base64string = 'data:image/png;base64,R0lGODlhEAAOALMAAOazToeHh0tLS/7LZv/0jvb29t/f3//Ub//ge8WSLf/rhf/3kdbW1mxsbP//mf///yH5BAAAAAAALAAAAAAQAA4AAARe8L1Ekyky67QZ1hLnjM5UUde0ECwLJoExKcppV0aCcGCmTIHEIUEqjgaORCMxIC6e0CcguWw6aFjsVMkkIr7g77ZKPJjPZqIyd7sJAgVGoEGv2xsBxqNgYPj/gAwXEQA7';
file_put_contents('img.png', base64_decode(explode(',',$base64string)[1]));
PHP has already a fair treatment base64 -> file transform
I use to get it done using this way:
$blob=$_POST['blob']; // base64 coming from an url, for example
$blob=file_get_contents($blob);
$fh=fopen("myfile.png",'w'); // be aware, it'll overwrite!
fwrite($fh,$blob);
fclose($fh);
echo '<img src=myfile.png>'; // just for the check
try this...
$file = $_POST['file']; //your data in base64 'data:image/png....';
$img = str_replace('data:image/png;base64,', '', $file);
file_put_contents('img/imag.png', base64_decode($img));
If you want to randomly rename images, and store both the image path on database as blob and the image itself on folders this solution will help you. Your website users can store as many images as they want while the images will be randomly renamed for security purposes.
Generate random varchars to use as image name.
function genhash($strlen) {
$h_len = $len;
$cstrong = TRUE;
$sslkey = openssl_random_pseudo_bytes($h_len, $cstrong);
return bin2hex($sslkey);
}
$randName = genhash(3);
#You can increase or decrease length of the image name (1, 2, 3 or more).
Get image data extension and base_64 part (part after data:image/png;base64,) from image .
$pos = strpos($base64_img, ';');
$imgExten = explode('/', substr($base64_img, 0, $pos))[1];
$extens = ['jpg', 'jpe', 'jpeg', 'jfif', 'png', 'bmp', 'dib', 'gif' ];
if(in_array($imgExten, $extens)) {
$imgNewName = $randName. '.' . $imgExten;
$filepath = "resources/images/govdoc/".$imgNewName;
$fileP = fopen($filepath, 'wb');
$imgCont = explode(',', $base64_img);
fwrite($fileP, base64_decode($imgCont[1]));
fclose($fileP);
}
# => $filepath <= This path will be stored as blob type in database.
# base64_decoded images will be written in folder too.
# Please don't forget to up vote if you like my solution. :)
This code works for me check below code:
<?php
define('UPLOAD_DIR', 'images/');
$image_parts = explode(";base64,", $_POST['image']);
$image_type_aux = explode("image/", $image_parts[0]);
$image_type = $image_type_aux[1];
$image_base64 = base64_decode($image_parts[1]);
$file = UPLOAD_DIR . uniqid() . '.png';
file_put_contents($file, $image_base64);
?>
Total concerns:
$data = 'data:image/png;base64,AAAFBfj42Pj4';
// Extract base64 file for standard data
$fileBin = file_get_contents($data);
$mimeType = mime_content_type($data);
// Check allowed mime type
if ('image/png'==$mimeType) {
file_put_contents('name.png', $fileBin);
}
It worth to say that discussed topic is documented in RFC 2397 - The "data" URL scheme (https://tools.ietf.org/html/rfc2397)
Because of this PHP has a native way to handle such data - "data: stream wrapper" (http://php.net/manual/en/wrappers.data.php)
So you can easily manipulate your data with PHP streams:
$data = 'data:image/gif;base64,R0lGODlhEAAOALMAAOazToeHh0tLS/7LZv/0jvb29t/f3//Ub//ge8WSLf/rhf/3kdbW1mxsbP//mf///yH5BAAAAAAALAAAAAAQAA4AAARe8L1Ekyky67QZ1hLnjM5UUde0ECwLJoExKcppV0aCcGCmTIHEIUEqjgaORCMxIC6e0CcguWw6aFjsVMkkIr7g77ZKPJjPZqIyd7sJAgVGoEGv2xsBxqNgYPj/gAwXEQA7';
$source = fopen($data, 'r');
$destination = fopen('image.gif', 'w');
stream_copy_to_stream($source, $destination);
fclose($source);
fclose($destination);
This function should work. this has the photo parameter that holds the base64 string and also path to an existing image directory should you already have an existing image you want to unlink while you save the new one.
public function convertBase64ToImage($photo = null, $path = null) {
if (!empty($photo)) {
$photo = str_replace('data:image/png;base64,', '', $photo);
$photo = str_replace(' ', '+', $photo);
$photo = str_replace('data:image/jpeg;base64,', '', $photo);
$photo = str_replace('data:image/gif;base64,', '', $photo);
$entry = base64_decode($photo);
$image = imagecreatefromstring($entry);
$fileName = time() . ".jpeg";
$directory = "uploads/customer/" . $fileName;
header('Content-type:image/jpeg');
if (!empty($path)) {
if (file_exists($path)) {
unlink($path);
}
}
$saveImage = imagejpeg($image, $directory);
imagedestroy($image);
if ($saveImage) {
return $fileName;
} else {
return false; // image not saved
}
}
}
Source: Stackoverflow.com