PHP convert an image made in the file into base64

Question

I have an image that I have created by combining images based on database data, and was wondering hw to convert that to base 64. I tried this but the characters returned can not be decoded into an image:

$encode ="data:image/png"; 
imagepng($image);
echo (base64_encode($encode));

I saw this among others but that requires a path that I don't have. Thanks for any help.

score 5 · Accepted Answer · edited Jun 20 '20 at 09:12

5

The following will allow you to get the image data without having to create a temporary file (I've had nightmares with temporary files before when too many users were online...)

ob_start(function($c) {return "data:image/png;base64,".base64_encode($c);});
imagepng($image);
ob_end_flush();

This will output something similar to:

data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQAgMAAABinRfyAAAAAXNSR0IArs4c6QAAAAxQTFRFAGVygICA/8wz/+aZTn6FEAAAAAF0Uk5TAEDm2GYAAAABYktHRACIBR1IAAAACXBIWXMAAAsTAAALEwEAmpwYAAAAB3RJTUUH2wkZEwoSgxq4wwAAAB1pVFh0Q29tbWVudAAAAAAAQ3JlYXRlZCB3aXRoIEdJTVBkLmUHAAAAS0lEQVQI1w3EMQ3AMAwEwMdTEmWRSF68h0RQBIKl5vkUirdGX99wuKUPKkjJkfM4jueE+ivo7VW6wDCCq1VtEdtiIMY2BGlgwUU+P38ZK+RwskeQAAAAAElFTkSuQmCC

Which is suitable for use inside an <img src="..." />.

Edit For PHP < 5.3 without anonymous functions:

// Define the function first
function ob_base64_encode($c) {
  return "data:image/png;base64,".base64_encode($c);
}
// And pass its name as a string
ob_start('ob_base64_encode');
imagepng($image);
ob_end_flush();

edited Jun 20 '20 at 09:12

Community

1
1

answered May 20 '12 at 19:18

Niet the Dark Absol

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This gives me an error Parse error: syntax error, unexpected T_FUNCTION, expecting ')' – jersam515 May 20 '12 at 19:23
@jersam515 You must have a PHP version older than 5.3 so the anonymous function is not permitted. Define the function with a name and pass the string name as a callback. – Michael Berkowski May 20 '12 at 19:29
@Kolink, hope you don't mind the edit. This was a good answer and I want to make it work for the OP. – Michael Berkowski May 20 '12 at 19:31
@Michael - Thanks, I guess I'm just used to having control over what PHP version I use XD At least I haven't used `[...]` array syntax or array dereferencing in an answer yet :p – Niet the Dark Absol May 20 '12 at 19:49
@Kolink <3 array literals and function dereferencing in 5.4 <3 <3 <3 – Michael Berkowski May 20 '12 at 19:52
@Michael And the build-in development server! I didn't want to install a full production server just to test on, so I had made my own server in PHP but it was kinda buggy. This new stuff is awesome! – Niet the Dark Absol May 20 '12 at 19:54

score 1 · Answer 2 · answered May 20 '12 at 19:16

You are encoding the string "data:image/png" - naturally you won't be able to decode it into an image. Assuming $image contains valid image data, you should be able to simply do

imagepng($image, $temp_file_name);
base64_encode(file_get_contents($temp_file_name));

score 0 · Answer 3 · edited May 23 '17 at 11:50

from manuals: http://php.net/manual/en/function.base64-encode.php#105200

/**
 * Returns base64 encoded string prepended by "data:image/"
 *
 * @param $filename string
 * @param $filetype string 
 * @return string
 */
 function base64_encode_image($filename=string, $filetype=string)
 {
     if ($filename) {
         $imgbinary = fread(fopen($filename, "r"), filesize($filename));
             return 'data:image/' . $filetype 
                    . ';base64,' . base64_encode($imgbinary);
    }
}

Function code by luke at lukeoliff.com.

Function comments by me.

PHP convert an image made in the file into base64

3 Answers3

Edit For PHP < 5.3 without anonymous functions: