Question

I am using PHP to generate images and this works fine. I am having trouble displaying these images however:

My image generator is a PHP file that takes tons of parameters and loads of data to generate the image. Because of the excessive amounts that has to be passed to the generator, using the GET container does not work for me, so the data is sent via a POST request. The result of this request is the raw image data.

I am using

$result = post_request('http://myurl.com/graphx/generator.php', $data);
if($result['status'] == 'ok') {
    echo "<img src=\"data:image/png;base64,".
        base64_encode($result['content'])."\"/>\n";
}

to display my image. This works for very small images, but as they get bigger (300px*300px for example), the image is not displayed anymore (it seems to be cut somewhere).

Is my approach reasonable?

Is there any workaround for the size issue?

Update:

When I let the generator save the image to a file, the created file contains the image as I want it to be. Also, if convert my generator into a GET-generator, the following code works properly as well:

$data = http_build_query($data);
echo "<img src=\"http://myurl.com/graphx/get_generator.php?{$data}\"/>\n";

So it definitely seems to be a problem with either the POST request, or the conversion into the base64 format. I’m using the POST request as shown here.

Answer 1

I’d suggest having your page be structured like this:

main page:

<img src="imageproxy.php" />

imageproxy.php:

<?php
$result = post_request('http://myurl.com/graphx/generator.php', $data);
header('Content-type: image/png');
if($result['status'] == 'ok') {
    echo $result['content']);
} else {
    readfile('error_message_image.png');
}

instead of trying to work with data uris and length limits, just have your proxy script output the actual raw image data and treat it as an image in your client-side html.